MIKE HYDRO Basin User Guide

MIKE HYDRO Basin User Guide
MIKE HYDRO
Basin
User Guide
MIKE 2017
2
MIKE HYDRO - © DHI
PLEASE NOTE
COPYRIGHT
This document refers to proprietary computer software which is protected by copyright. All rights are reserved. Copying or other reproduction of this manual or the related programmess is prohibited
without prior written consent of DHI. For details please refer to your
‘DHI Software Licence Agreement’.
LIMITED LIABILITY
The liability of DHI is limited as specified in Section III of your ‘DHI
Software Licence Agreement’:
‘IN NO EVENT SHALL DHI OR ITS REPRESENTATIVES
(AGENTS AND SUPPLIERS) BE LIABLE FOR ANY DAMAGES
WHATSOEVER INCLUDING, WITHOUT LIMITATION, SPECIAL,
INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR
DAMAGES FOR LOSS OF BUSINESS PROFITS OR SAVINGS,
BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION OR OTHER PECUNIARY LOSS ARISING OUT OF THE
USE OF OR THE INABILITY TO USE THIS DHI SOFTWARE
PRODUCT, EVEN IF DHI HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THIS LIMITATION SHALL APPLY
TO CLAIMS OF PERSONAL INJURY TO THE EXTENT PERMITTED BY LAW. SOME COUNTRIES OR STATES DO NOT ALLOW
THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL, SPECIAL, INDIRECT, INCIDENTAL DAMAGES AND,
ACCORDINGLY, SOME PORTIONS OF THESE LIMITATIONS
MAY NOT APPLY TO YOU. BY YOUR OPENING OF THIS
SEALED PACKAGE OR INSTALLING OR USING THE SOFTWARE, YOU HAVE ACCEPTED THAT THE ABOVE LIMITATIONS
OR THE MAXIMUM LEGALLY APPLICABLE SUBSET OF THESE
LIMITATIONS APPLY TO YOUR PURCHASE OF THIS SOFTWARE.’
3
4
MIKE HYDRO - © DHI
CONTENTS
MIKE HYDRO Basin User Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2
Working With MIKE HYDRO . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
3
How to Start MIKE HYDRO . . . .
The MIKE HYDRO User Interface .
2.2.1
Tree view . . . . . . . . .
2.2.2
Map view and tabular view
2.2.3
Property view . . . . . . .
2.2.4
Output windows . . . . . .
2.2.5
Ribbon . . . . . . . . . .
2.2.6
Menu bar . . . . . . . . .
Layout . . . . . . . . . . . . . . .
MIKE Zero Menu Bar . . . . . . . .
2.4.1
File menu . . . . . . . . .
2.4.2
Edit menu . . . . . . . . .
2.4.3
View menu . . . . . . . .
2.4.4
Run . . . . . . . . . . . .
2.4.5
Tools . . . . . . . . . . .
Creating Input Files . . . . . . . . .
2.5.1
Create a new dfs0 file . . .
Viewing Results . . . . . . . . . .
2.6.1
Basin result files . . . . .
2.6.2
Dfs0 files . . . . . . . . .
Getting Help . . . . . . . . . . . .
Examples . . . . . . . . . . . . . .
2.8.1
Basin module examples .
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17
18
18
22
24
25
27
29
29
31
31
32
32
34
34
34
35
37
38
38
39
39
39
Tutorial: Setting Up a Simple Model . . . . . . . . . . . . . . . . . . . . . . . 43
3.1
Setting up a Simple Basin Model . . . . .
3.1.1
Create a new document . . . .
3.1.2
Define simulation specifications
3.1.3
Create the River network . . . .
3.1.4
Create a Catchment . . . . . .
3.1.5
Insert a Reservoir . . . . . . . .
3.1.6
Insert two Water users . . . . .
3.1.7
Insert a Hydropower plant . . .
3.1.8
Validate the setup . . . . . . . .
3.1.9
Running a simulation . . . . . .
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43
43
43
44
44
44
44
45
45
45
5
3.1.10
4
Simulation Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.1
4.2
4.3
4.4
4.5
5
5.5
6.2
6.3
6.4
6.5
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Coordinate System . . . . . . . . . . . . . . .
Background Map . . . . . . . . . . . . . . . . .
Background Layers . . . . . . . . . . . . . . .
Digital Elevation Model (DEM) . . . . . . . . . .
5.4.1
River tracing and catchment delineation
Working Area . . . . . . . . . . . . . . . . . .
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47
49
51
52
53
54
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55
56
56
57
57
58
. . . . . . . . . . . . . . . . . . . . . . . . .
Creating a River Network . . . . . . . . . . . . . . . . .
6.1.1
Method 1: Digitising a River network . . . . . . .
6.1.2
Method 2: Importing a River network . . . . . . .
6.1.3
Method 3: Derive the River network from a DEM
Branches . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.1
General . . . . . . . . . . . . . . . . . . . . . .
6.2.2
User defined chainage points . . . . . . . . . .
River Nodes . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1
Flow loss time series . . . . . . . . . . . . . . .
6.3.2
Flow capacity time series . . . . . . . . . . . .
6.3.3
Bifurcation type and associated data . . . . . . .
Priority Nodes . . . . . . . . . . . . . . . . . . . . . . .
6.4.1
Minimum flow . . . . . . . . . . . . . . . . . . .
6.4.2
Priorities . . . . . . . . . . . . . . . . . . . . .
Routing . . . . . . . . . . . . . . . . . . . . . . . . . .
6.5.1
Routing method . . . . . . . . . . . . . . . . .
6.5.2
Water level Calculation . . . . . . . . . . . . . .
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61
61
62
62
63
63
63
64
65
66
66
67
67
68
68
69
69
72
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75
77
78
80
82
82
95
98
98
99
Catchments
7.1
7.2
7.3
6
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River Network
6.1
7
Modes . . . . . . . . . . . . . . .
4.1.1
Basin modules . . . . . .
Description . . . . . . . . . . . . .
Simulation Period . . . . . . . . .
Time Step Control . . . . . . . . .
Computational Control Parameters
Map Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.1
5.2
5.3
5.4
6
Inspecting the results . . . . . . . . . . . . . . . . . . . . . . . . . . 45
. . . . . . . .
Catchment definitions .
7.1.1
General . . . .
7.1.2
Groundwater .
7.1.3
Rainfall-Runoff
7.1.4
NAM . . . . .
7.1.5
UHM . . . . .
7.1.6
Sediment Load
Combined Catchments
Hotstart files . . . . . .
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MIKE HYDRO - © DHI
8
Water Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
8.1
8.2
8.3
8.4
8.5
8.6
9
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.1
Type of water user . . . . . . . . . . . . . . . . . . . . .
8.1.2
Water demand time series and demand carry-over fraction
8.1.3
Groundwater properties . . . . . . . . . . . . . . . . . . .
Supply Connections . . . . . . . . . . . . . . . . . . . . . . . . .
8.2.1
Priority of supply connections . . . . . . . . . . . . . . . .
8.2.2
Flow loss time series . . . . . . . . . . . . . . . . . . . .
8.2.3
Flow capacity time series . . . . . . . . . . . . . . . . . .
Return Flow Connections . . . . . . . . . . . . . . . . . . . . . .
8.3.1
Return flow time series . . . . . . . . . . . . . . . . . . .
8.3.2
Flow loss time series . . . . . . . . . . . . . . . . . . . .
8.3.3
Flow capacity time series . . . . . . . . . . . . . . . . . .
Irrigation Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4.1
Climate model . . . . . . . . . . . . . . . . . . . . . . .
8.4.2
Deficit distribution method . . . . . . . . . . . . . . . . .
8.4.3
Use a soil and runoff model for all fields . . . . . . . . . .
Irrigated Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Irrigation Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.6.1
Irrigation method . . . . . . . . . . . . . . . . . . . . . .
8.6.2
Crops . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.6.3
Soil and runoff . . . . . . . . . . . . . . . . . . . . . . .
8.6.4
References . . . . . . . . . . . . . . . . . . . . . . . . .
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103
103
103
104
106
106
107
107
108
108
108
109
109
109
110
111
111
113
113
117
121
126
Reservoirs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
9.1
9.2
9.3
9.4
9.5
9.6
General . . . . . . . . . . . . . . . . . . . . . .
9.1.1
Reservoir type . . . . . . . . . . . . .
9.1.2
Level-area-volume (LAV) table . . . . .
9.1.3
Characteristic levels time series . . . .
9.1.4
Losses and gains time series (optional)
9.1.5
Sediment distribution type . . . . . . .
Operations . . . . . . . . . . . . . . . . . . . .
9.2.1
Lakes . . . . . . . . . . . . . . . . . .
9.2.2
Rule curve reservoirs . . . . . . . . . .
9.2.3
Allocation pool reservoirs . . . . . . . .
Users . . . . . . . . . . . . . . . . . . . . . . .
9.3.1
Priority . . . . . . . . . . . . . . . . .
9.3.2
Number of reduction levels . . . . . . .
9.3.3
Pool ownership time series . . . . . . .
9.3.4
Flow loss time series . . . . . . . . . .
9.3.5
Flow capacity time series . . . . . . . .
Remote Flow Control . . . . . . . . . . . . . . .
Storage Demand . . . . . . . . . . . . . . . . .
Spillways . . . . . . . . . . . . . . . . . . . . .
9.6.1
Spill capacity table . . . . . . . . . . .
9.6.2
Spillway bottom level time series . . . .
9.6.3
Bottom outlet capacity time series . . .
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128
128
129
129
129
130
132
132
133
134
135
135
136
138
139
140
140
141
141
142
142
142
7
9.7
10
Guide Curve Level (for Global Ranking) . . . . . . . . . . . . . . . . . . . .
144
Hydropower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
147
148
149
149
150
151
151
10.1
10.2
10.3
10.4
10.5
10.6
11
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Global Ranking Parameters . . . . . . . . . . . . . . . . . . . . . . . . . .
Sediment Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Notes on ECO Lab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water quality definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Result Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.1
15
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Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.1
13.2
14
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Sediment Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.1
13
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Global Ranking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.1
12
Power Demand Time Series . . . . . . . . . .
Head Approximation . . . . . . . . . . . . . .
Use Minimum Release from Reservoir Option
Tailwater . . . . . . . . . . . . . . . . . . . .
Power Efficiency Table . . . . . . . . . . . .
Head Loss Table . . . . . . . . . . . . . . . .
Standard Results
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main menu bar features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.1
15.2
File: Import and Export of MIKE HYDRO data
15.1.1 Import . . . . . . . . . . . . . . .
15.1.2 Export . . . . . . . . . . . . . . .
Tools . . . . . . . . . . . . . . . . . . . . .
15.2.1 Tools: Load Calculator . . . . . . .
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153
153
159
160
163
163
163
169
169
171
171
171
173
176
177
Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Appendix A
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
183
A.1
THE LINEAR RESERVOIR MODEL . . . . . . . . . . . . . . . . . . . . . . . . .
185
A.2
HYDROPOWER - FORMULA . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
187
A.3
IRRIGATION . . . . . . . . . . . . . . . . .
A.3.1 Climate Models . . . . . . . . . . . .
A.3.2 Reference ET Time Series Calculation
A.3.2.1 Reference ET time series . .
A.3.2.2 FAO 56 reference ET . . . .
A.3.3 Crops . . . . . . . . . . . . . . . . .
A.3.4 Soil Model . . . . . . . . . . . . . . .
A.3.4.1 FAO 56 . . . . . . . . . . . .
A.3.4.2 ZIMsched . . . . . . . . . . .
A.3.5 Runoff Model . . . . . . . . . . . . .
189
189
189
189
189
191
191
192
196
198
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MIKE HYDRO - © DHI
A.3.5.1 Using the Runoff model or not . . . . . . . . . . . . . . . . . . . . 198
A.3.5.2 Available Runoff models . . . . . . . . . . . . . . . . . . . . . . . 199
A.4
REFERENCES
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
B.1
RESERVOIR SEDIMENTATION IN MIKE HYDRO BASIN . . . . . . . . . . . . . . 207
B.1.1 Prediction of reservoir trap efficiency . . . . . . . . . . . . . . . . . . . . . . 207
B.1.2 Update of reservoir storage surface curve . . . . . . . . . . . . . . . . . . . 208
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
9
10
MIKE HYDRO - © DHI
MIKE HYDRO BASIN USER GUIDE
11
12
MIKE HYDRO - © DHI
1
Introduction
MIKE HYDRO is the common Graphical User Interface framework some of
the Water Resources products of MIKE Powered by DHI.
Embedded in one setup editor, MIKE HYDRO offers a state-of-art, map-centric user interface for intuitive model build, parameter definition and results
presentation for water resources related applications.
MIKE HYDRO includes the following modules:

Basin module

River module
Basin module
MIKE HYDRO Basin is a versatile and highly flexible model framework for a
large variety of applications concerning Management and Planning aspects
of water resources within a river basin.
Typical basin module applications


Integrated Water Resources Management (IWRM) studies
Multi-sector solution alternatives to water allocation and water shortage
problems

Reservoir and hydropower operation optimisation

Exploration of conjunctive use of groundwater and surface water

Irrigation scheme performance improvements
13
Introduction
Features
MIKE HYDRO Basin models utilise a river network and catchments within the
specific river basin as the basic model-data. On top of this, a number of features can be applied depending on the type of application. Features include;
River routing, Water users (regular as well as Irrigation users), Hydro power
and Reservoirs, Hydrology (rainfall-runoff simulations), Groundwater, Global
ranking of water users, Reservoir sedimentation and Water quality options
using ECO Lab.
MIKE HYDRO Basin is the successor of DHI’s former product for Integrated
water resources management and planning; ‘MIKE BASIN’.
River module
MIKE HYDRO River is the modelling framework for defining and executing
one-dimensional river models to a large variety of river related project applications.
River module applications
Typical application areas with river models include:
14

River hydraulics application

Flood analysis and flood alleviation design studies

Real time flood or drought forecasting

Dam break analysis

Optimisation of reservoir and gate operations

Ecology and water quality assessments in rivers and wetlands

Water quality forecasting
MIKE HYDRO - © DHI


Sediment transport and long term assessment of river morphology
changes
Wetland restoration studies
MIKE HYDRO River is the new generation of Graphical User Interface for
MIKE by DHI River modelling applications, and MIKE HYDRO River is hence
the successor for the existing DHI river modelling package; MIKE 11.
For more information see MIKE HYDRO River User Guide.
15
Introduction
16
MIKE HYDRO - © DHI
How to Start MIKE HYDRO
2
Working With MIKE HYDRO
This section includes an overview of the different components in the MIKE
HYDRO graphical user interface and how to use them.
The general functionality of the individual windows is described in this section, whereas any specific functionality only available in special cases will be
described later.
2.1
How to Start MIKE HYDRO
During the installation of MIKE HYDRO a shortcut for ‘MIKE Zero’ is placed in
the Start menu. When MIKE Zero is started the MIKE Zero shell is displayed.
To create a new MIKE HYDRO setup go to the File menu and choose New
and File, which will open the dialogue window shown in Figure 2.1. Select
‘MIKE HYDRO Model’ from the MIKE HYDRO product type group and press
the ‘OK’ button or double-click the icon to create a new MIKE HYDRO document.
Figure 2.1
Create new MIKE HYDRO document
Creating a new MIKE HYDRO document automatically starts a MIKE HYDRO
setup wizard.
The wizard will guide you through defining key settings for the framework of
your project. Pressing Cancel in the wizard will use default parameters.
Note that any settings specified in the setup wizard may later be changed
from the individual dialogue boxes.
17
Working With MIKE HYDRO
If the setup wizard will not be used in future projects, uncheck the checkmark
on the first page of the wizard or change the settings in the User Settings see
section User settings (p. 32).
2.2
The MIKE HYDRO User Interface
The MIKE HYDRO User Interface consists of six main parts (see Figure 2.2):
Figure 2.2
2.2.1

Tree view

Map view and tabular view

Property view

Output windows

Ribbon

Menu bar
MIKE HYDRO User Interface
Tree view
The tree view contains three tabs:
18

- control of model parameters

- control of symbology and labels
MIKE HYDRO - © DHI
The MIKE HYDRO User Interface

- view simulation results
Setup tree view
The Setup tree view allows you to navigate easily between the different sets
of model setup parameters. Each node in the tree corresponds to a particular
set of parameters, and clicking the node will navigate to the particular set of
parameters which will be displayed in the Property view as well as in the Tabular view.
The tree depends on the settings in the Modules page (see User Guide 4.1
Modes (p. 47)) and will only show relevant nodes.
The Setup tree view also displays the validation status of the parameters – if
a green tick mark is displayed on the tree node, this group of setup parameters has been validated without errors. In case of warnings or errors, a red
cross is displayed in the tree node and the messages are displayed in the
Validation window.
Note: A green validation tick mark is displayed if the model setup parameter
node has been opened. It is therefore possible to execute simulations without
green tick marks in all tree nodes.
Symbology tree view
The Symbology tree view allows you to select the objects for which you want
to edit the appearance in the Map view. The tree displayed under the Symbology tab matches the tree displayed in the Setup tab for all objects shown on
the map.
The symbology of the Map view shown under the Result tab is specified
under the ‘Results’ node in the tree view.
Symbology
For each object type it is possible to edit the symbology on Symbol tab. The
symbology can be shown or hidden on the map using the setting ‘Visible’.
Note that the ‘Visible’ setting can also be changed by double-clicking on the
symbol in the tree view.
Changes in the symbology is reflected on the map when pressing ‘Apply to
map’ at the bottom of the tabular view. The symbology is automatically
applied when changing to the Setup or Result tree view.
Note that by right-clicking on an object in the tree view you can choose ‘Reset
symbology’ and this will set the symbology for the selected object back to the
default symbology.
Symbology settings are saved with the project.
19
Working With MIKE HYDRO
The symbology settings will differ based on the object type e.g. line, point,
symbol or polygon.
In general all elements will have 4 symbology types:

Single symbol

Graduated size

Graduated color

Unique values
Single symbol
Using the single symbol will display all elements on the map with a common
symbology.
For point objects it is possible to define the symbol style as either ‘Simple
symbol’ defining colour and size or as ‘Picture symbol’ using predefined pictures.
Graduated size
Using the graduated size will display the elements with different size or width
depending on a user-specified parameter.
The general settings for the symbology is defined as for single symbols with
the exception of the size which is defined with a minimum and maximum size.
The parameter used for differentiating the size is defined in the ‘Field’ and
can only be numeric values.
A grid is defined at the bottom for specifying the intervals used for different
sizes. The number of intervals are changed by using the ‘Classify’ button.
This will open a dialogue for defining the number of classes and the corresponding break values.
Note that the button ‘Distribute equidistant’ will set the break values according
to the current values used in the setup.
Break values can be changed either in the ‘Classify’ dialogue or directly in the
grid for existing classes. In the case where the break values does not cover
the entire range of values in the setup a default size may be applied by setting the parameter ‘Use default symbology’. If this is not specified elements
not falling within the specified interval will be hidden on the map.
Graduated size is not available for polygons.
Graduated color
Using the graduated color will display the elements with different color
depending on a user-specified parameter.
20
MIKE HYDRO - © DHI
The MIKE HYDRO User Interface
The general settings for the symbology is defined as for single symbols with
the exception of the colour which is defined as a colour ramp. The parameter
used for differentiating the size is defined in the ‘Field’.
Colour ramps can be modified using the color palette wizard. Documentation
of the wizard is available in the common MIKE Zero documentation installed
with the standard MIKE HYDRO Basin installation: “The Common DHI User
Interface for Project Oriented Water Modelling”: User Guide (...MIKE
Zero\Manuals\MIKE_ZERO\MIKEZero.pdf).
A grid is defined at the bottom for specifying the intervals used for different
colours. The number of intervals are changed by using the ‘Classify’ button.
This will open a dialogue for defining the number of classes and the corresponding break values.
Note that the button ‘Distribute equidistant’ will set the break values according
to the current values used in the setup.
Break values can be changed either in the ‘Classify’ dialogue or directly in the
grid for existing classes. In the case where the break values does not cover
the entire range of values in the setup a default colour may be applied by setting the parameter ‘Use default symbology’. If this is not specified elements
not falling within the specified interval will be hidden on the map.
Unique Values
Using the unique values will display individual symbology depending on a
user-specified parameter. The parameter used for differentiating the symbol
is defined in the ‘Field’.
A grid is defined at the bottom for specifying the relation between symbology
and value. New entries in the grid is added using the either ‘Add’ for one
value or ‘Add all’ for all values currently in the setup. The symbol for each
value in the grid is changed by double-clicking on the symbol in the grid.
In the case where a value is not specified in the grid a default symbol may be
applied by setting the parameter ‘Use default symbology’. If this is not specified elements not falling within a specified value will be hidden on the map.
Labels
For each object type it is possible to edit the labels on Label tab. The label
can be shown or hidden on the map using the setting ‘Visible’.
Label settings are saved with the project.
Map Properties
Map properties are specified under ‘Map configuration’ in the tree view. Here
options are provided for displaying a legend, scalebar and north arrow on the
map.
The legend will only display elements shown in the map.
21
Working With MIKE HYDRO
Results tree view
The Results tree view allows you to navigate easily between the different simulation results (model outputs). Each node in the tree corresponds to a particular set of simulation results, and clicking the node will navigate to that set
of simulation results.
For more information on how to view results see section 2.6 Viewing Results
(p. 37).
2.2.2
Map view and tabular view
The central part of the user interface has the following two views:

Map view

Tabular view
Map view
The Map view is the key element of MIKE HYDRO. Map view provides a
graphical – or map – view of the model setup. In Map view, the different
model objects (e.g. Branches) can be added and edited by selecting the
appropriate model object tab in the ribbon.
Right-clicking on the map will provide quick access to zoom functions and
exporting the map either to the clipboard or a file.
Selection tools
A set of useful tools is available to identify or select specific features defined
in the map view. Tools are located in the ‘Selection’ ribbon bar group with the
following features:


22
Identity: Identify button is used to identify and highlight specific model
objects. Identify has two ways of operation; when activated at a location
where only one single object is defined, it will automatically activate the
specific object both in the Property view and activate the Tabular view for
the specific object. If Identify is activated at a location where multiple
objects are located, a list of objects are presented and the user can
select which object should be activated.
Select: Enable selection of model objects. Selections can be made
through single click on the map or by drawing a rectangle. All objects
positioned at the specified location will be selected and highlighted.

Unselect: Removes all selections within the map

Delete selection: Deletes all the selected objects

Zoom to selection: Zooms to all selected objects on the map
MIKE HYDRO - © DHI
The MIKE HYDRO User Interface
Undo and redo
MIKE HYDRO supports undo and redo on operations on the map and
changes in the tabular view or property view.
If the cursor is placed over either undo or redo buttons the hint will list the
change that will be either re- or undone.
In general all type of data for the network is covered by undo and redo functionality where as changes to the layout and display of data is not.
The following is not covered by undo and redo functionality:

Symbology and labels

Result presentations

Windows layout

Selections

Changes to water quality definitions

Pop-up windows
Measure tool
The measure tool allows to measure distances between points in the Map or
along a path. This tool is located in the ribbon in the upper part of the Map
view page.
When pressing the Measure icon, a dialogue pops up. In this dialogue it is
possible to choose between two options:


Line. When this option is selected, the distance is calculated along a
straight line. The first click on the map locks the start point of the line.
While the cursor moves on the map it is possible to see the line along
which the distance is measured. At the same time, the length of the line
is displayed in the dialogue.
Path. This option must be selected to measure length along paths that
are not straight. The first click on the map select the start point of the
path. When the cursor moves further on the map and additional points
are selected with a click, the distance from the start point are added to
the measured length and displayed in the measure tool window. The
specified path it is not visible on the map.
In the lower right corner of the Measure tool dialogue, the following two buttons are shown:
Clear. Click on this button to reset to 0 the distance displayed in the Measure
tool dialogue.
Close. Click on this button to close the Measure tool dialogue.
23
Working With MIKE HYDRO
Tabular view
The Tabular view provides a dialogue-style interface to the model parameter
group selected in the tree view. In the Tabular view the properties of the
model parameter groups are specified and edited. In some cases the Tabular
view consists of one or more pages. Multiple pages will be shown as tabs
which may be shown or hidden based on the individual parameter settings.
In general the tabular view is divided into an upper part with fields and a lower
part with an overview table. When changing between records in the overview
table the upper part will be updated with parameters for the active record.
Overview table
The overview table contains all attributes for the object group. The records
can be sorted by clicking on the header.
One or more cells can be copied to the clipboard by selecting the relevant
cells (they will turn blue) and either right-clicking and choose ‘Copy’ or use
Ctrl+C.
One or more cells can be pasted to the table by standing in the top left cell of
the group of cells to be overwritten and either right-clicking and choose
‘Paste’ or use Ctrl+V. Any value pasted to a read-only cell will be ignored.
Note that in tables related to some objects displayed on the map e.g.
branches and catchments it is not possible to add new records - only existing
records will be overwritten. For other tables new records are created.
In order to delete several objects in the table the entire row must be selected
by clicking on the very left column in the grid (row will turn blue) and clicking
‘Delete’ on the keyboard.
Right-clicking in a table related to objects displayed on the map will give the
option ‘Zoom to active’. This will zoom the Map view to the active record.
For tables related to objects displayed on the map the first column is a checkmark. The checkmark shows if the element is selected on the map. The
selection status can be changed either in from the map or the overview table.
Selected attributes in the Tabular view has a corresponding line in the Property window. The Tabular view and the Property window are synchronised – a
change in either will be reflected in the other. Thus, the same parameters can
be edited in either of the two views.
2.2.3
Property view
The Property view provides another way of displaying and editing the properties of model parameter groups – including the model objects. The same
properties can be edited through the Tabular view. The two places are syn-
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The MIKE HYDRO User Interface
chronised – any change made in the Tabular view is reflected in the Property
view and vice versa.
The Property view will show properties for the active model object group. The
data is grouped by a unique identifier (ID) and the ID is highlighted in dark
grey for the active record.
The Property window may be hidden by unselecting Property view in the
‘View’ drop-down menu in the MIKE Zero menu bar.
The content of Property window’ may be defined to either show all model
group objects or selected objects only by setting the ‘Property view: Showselected’ in the ‘View’ drop-down menu in the MIKE Zero menu bar.
2.2.4
Output windows
The Output windows can display a collection of different windows depending
on the situation. Per default the windows are shown as tabs. The individual
windows are described below.
All type of output windows may be shown or hidden by unselecting the output
window in the ‘View’ drop-down menu in the MIKE Zero menu bar. If new
information is shown in a hidden window the window will automatically be
shown.
Validation
The Validation window shows validation status messages and error messages. Each time a model object is edited e.g. changing data in the Tabular
view or the Property view the data is validated and any errors are shown in
the Validation window.
Some extended validation checks are not performed on the fly, but can manually be run by selecting ‘Extended validation’ from the ‘Run’ drop-down
menu in the MIKE Zero menu bar. Running the Extended validation will perform both the standard and extended validation checks.
Note that error messages from the extended validation checks are only
updated when a new extended validation is performed. Hence extended validation messages may still appear even if the error has been corrected.
Running a simulation will automatically perform an extended validation.
Simulation
The Simulation window shows progress and output from the computational
engine.
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Working With MIKE HYDRO
Time series
The Time series window is automatically shown when plotting either input or
output times series.
To add an input time series to the window, click on the
button next to the
time series in Tabular view and select ‘Add to new plot’ or ‘Add to current
plot’. An input time series may also be added to the window by clicking on the
input time series grid cell in the Property view. A
button will appear in
the right hand side of the cell and clicking on that button gives the options of
‘Add to new plot’ or ‘Add to current plot’.
To add an output time series to the window, navigate to the relevant model
parameter group in Result tree view, right click on the relevant model object in
the Property view and select the time series to be added to a new/current plot
in the Time Series window. See section 2.6 Viewing Results (p. 37) for more
details.
The Time Series window can contain one or more plots which are shown as
tabs. A plot can be renamed by right-clicking on the tab and selecting
‘Rename’.
A plot can contain one or more time series. The layout of a plot has 3 controls. The first control shown on the left contains a list of each time series in
the plot grouped by file name and time series type. Time series can be
removed from the plot by right-clicking and choosing ‘Remove’ on either an
individual time series or a group of time series.
The middle control shows the data of the time series. Depending on the focus
in the left control either one or a group of time series are shown in the middle
control. Data can be copied to the clipboard by selecting one or more cells
and either right-clicking and choosing ‘Copy’ or using ‘Ctrl+C’.
The right control shows all time series added to the plot. Right-clicking on the
plot provides a sub-menu for zooming, printing and user settings such as the
use of secondary axis, position of legends, etc.
The Symbology dialogue from the sub-menu gives access to full control for
specifying symbology, titles etc. for the plot.
Note on zoom in the window: Drawing a rectangle with the mouse from top
left to bottom right will zoom in and drawing a rectangle from bottom right to
top left will zoom out in the Time series window.
The configuration of plots is saved with the setup and will automatically
appear when the setup is reopened. Any time series not available (either
because they come from files that are not reloaded or because the files no
longer contain the specified time series) are automatically removed from the
plots.
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The MIKE HYDRO User Interface
2.2.5
Ribbon
The ribbon is located above the Map view and gives access to graphically
editing of the geographically positioned objects in the model. Each model
object will have a corresponding set of tools. The most common are
described below.
Select
Using the function Select will select the model object on the map. Choose
Select and then click on the element on the map. When an element is
selected it will change colour to light blue. The selected elements will also be
highlighted in the Property view.
For some model objects there are multiple types controlled by the same ribbon e.g. Structures. For these model objects the Select function will only
select objects of the active type (determined by the combobox Type in the
same ribbon), whereas the Select any function will select any object of the
active group.
Add
Using the function Add will add the model object on the map. Choose Add
and then click on the location on the map where the object should be
inserted. Some model objects can only be inserted on a branch e.g. river
nodes or structures. The cursor will change to a cross when the cursor is
located at a valid place on the map.
For some model objects it is possible to use the function Add X, Y which will
insert the object based on a user defined coordinate. If the given coordinate
is not valid the object will be inserted at the closest valid location.
Branches and Catchments have multiple options for Adding data:


Branches: ‘Add’ creates a branch polyline from user-defined digitisation
on the map. ‘Add trace’ will add a delineated (traced) river branch when
defining river branches through River tracing and Catchment
delineation using DEM
Catchments: ‘Add digitise’ creates a catchment polygon from userdefined digitisation on the map. ‘Add delineate’ add a delineated catchment when defining catchments through the River tracing and Catchment delineation using DEM
Note: the above functionality will add model objects one by one on the map. It
is also possible to import multiple objects at once, from a shape file, in which
case the location of objects is directly read from this shape file. To achieve
this, please see section Import from Shapefile.
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Working With MIKE HYDRO
Move
Using the function Move will move a model object on the map. Move option is
present for point data objects (e.g. Water users, Reservoirs, Hydro power
etc.).
Choose Move and then click on the object that should be moved. The
selected object will change colour to light blue and a small symbol
is
shown. When clicking on the symbol the model object can be dragged to a
new location.
For some model objects there are multiple types controlled by the same ribbon e.g. Structures. For these model objects the Move function will only move
objects of the active type (determined by the combobox Type in the same ribbon), whereas the Move any function will move any object of the active
group.
Edit
Using the function Edit will move a model object on the map. Edit option is
present for polyline or polygon data objects (e.g. branches, catchments). Edit
can be used to either edit the shape of a selected object or to move the entire
object.
Choose Edit and then click on the object that should be edited. The selected
object will change colour to light blue and a small symbol
is shown. When
clicking on the symbol the entire model object can be dragged to a new location.
Edit polyline or polygon features has the following options for vertices (or
points) in MIKE HYDRO:



Move vertices: Individual vertices can be moved by click and drag when
positioning the mouse cursor on top of an existing vertice.
Delete vertices: Individual vertices can be deleted by double-click when
positioning the mouse cursor on top of the point to be deleted
Add vertices: Additional vertices can be added with a single mouse click
by pointing to a location where the new vertice must be located.
Note: It can be advantageous to click and hold the mouse button down
for a second or so to insert a new point. This will avoid that a ‘fast singleclick’ unselects the actual feature.
Delete
Using the function Delete will delete a model object on the map. Choose
Delete and then click on the object that should be deleted. When the cursor is
close to an object that can be deleted it will change symbol to an arrow
.
When clicking on the map the object is deleted.
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MIKE HYDRO - © DHI
Layout
For some model objects there are multiple types controlled by the same ribbon e.g. Structures. For these model objects the Delete function will only
delete objects of the active type (determined by the combobox Type in the
same ribbon), whereas the Delete any function will delete any object of the
active group.
2.2.6
Menu bar
The menu bar contains functionality for viewing and working with your setup.
For details about the individual functionality see section 2.4 MIKE Zero Menu
Bar (p. 31).
2.3
Layout
MIKE HYDRO has an IDE-style user interface (IDE=Integrated Development
Environment) where all windows reside under a single parent window,
referred to as the MIKE Zero shell.
The shell contains dockable and collapsible child windows, tabbed windows
and splitters for resizing of child windows.
The default windows docking layout is shown in Figure 2.2, but the user may
change this.
A window is undocked by either right-clicking in the heading and selecting
‘Float’ or by dragging the heading away from its current position. If only a tab
in a parent window containing multiple tabs should be undocked then you can
either right-click or drag the individual tab.
A window is docked again by either right-clicking in the heading and selecting
‘Dock’ or by double-clicking the heading. In both cases the window will be
docked again at the last location it was docked.
A window can also be docked by manually placing the window at a new location. Select the heading of the window that should be docked and start dragging the window and a docking guide will appear (see Figure 2.3). While still
dragging the window move the cursor to the new location using the docking
guide, when the cursor is placed on the docking guide the location will be
highlighted in blue. Once the correct location is highlighted the left mouse
button is released and the window will be docked.
The docking guide will always relate to the active window, where the active
window is the window located below the position of the cursor.
The docking guide will display small symbols where a docking location is possible. In the middle are 9 locations relative to the active window, where the
new window can either be placed as a tab to the active window (middle symbol) or left/right/below/above the active window (symbols around the middle).
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Working With MIKE HYDRO
On the edge of the shell are 4 other locations relative to the shell, where the
new window can be placed to the left/right/top/bottom of the shell.
Figure 2.3
Docking guide
Right-clicking on a docked window gives the option of ‘Auto Hide’. This will
automatically hide the window when it is not in focus and only display a tab.
Clicking the tab will show the full window again.
MIKE HYDRO has three type of windows available: Map view, Tabular view
and standard views.
The Map view is fixed to the middle of the shell. It cannot be undocked,
moved or resized. The size of the map will automatically fit any available
space in the shell not used by other windows. Hence indirectly the map can
be resized by resizing the other windows.
The Tabular view can be both undocked and docked in any location within the
shell, however it needs to be docked with another window. The Tabular view
differs from standard windows because it cannot be closed.
The standard windows which includes the Tree view, Property view and Output windows can be hidden, undocked or docked in any location within the
shell.
Any changes made to the layout are automatically saved with the setup. It is
further possible to save a specific layout to a file and re-use in other project.
The layout can easily be reset to the default configuration through the View
menu. See section 2.4.3 View menu (p. 32) for further details.
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MIKE Zero Menu Bar
2.4
MIKE Zero Menu Bar
The MIKE Zero menu bar contains some menus that are generic to the common MIKE Zero framework and some that are specific to working with MIKE
HYDRO. For details about the common MIKE Zero framework see ‘MIKE
Zero, The Common DHI User Interface for Project Oriented Water Modelling,
User Guide’ referred to as the ‘MIKE Zero User Guide’ below.
2.4.1
File menu
The menus New, Open, Close, Close Project, Save, Save All, Save As, Save
Project As Template, VCS Control, Print Setup, Print Preview, Print and
Options are all part of the MIKE Zero framework see ‘MIKE Zero User Guide’
for more details.
Import
Import from shape file
A comprehensive shape file import (and export) feature is available, enabling
model components to be imported through shape files.
More details on the import from shape file option, see “Import from Shapefile”
on page 171
Import from MIKE 11
An existing MIKE 11 setup can be imported by selecting ‘Import’ in the ‘File’
drop-down menu in the MIKE Zero menu bar and choosing ‘Import from MIKE
11’.
For more details on importing from MIKE 11 files, see “Import from MIKE 11”
on page 173
Importing a MIKE 11 setup will change to River mode.
Import from ISIS
The main features of an ISIS set-up can be imported by selecting ‘Import’ in
the ‘File’ drop-down menu in the MIKE Zero menu bar and choosing ‘Import
from ISIS’.
Importing an ISIS setup will change to River mode.
Export
Export to shape files
Model objects can be exported by selecting ‘Export’ in the ‘File’ drop-down
menu in the MIKE Zero menu bar and choosing ‘Export to shape files’.
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Working With MIKE HYDRO
All shape files are exported in the coordinate system for features (see 5.1
Coordinate System (p. 55))
For additional details on export to shape files, see “Export to Shapefile” on
page 173
Export to MIKE 11 files
Note: Export to MIKE 11 files is only available when operating in the River
mode of MIKE HYDRO.
Print
All print functionality is related to the Map View.
Options
Install examples
Several examples are included in the MIKE HYDRO installation. Select
MIKE_HYDRO in the pop-up menu and click ‘Install’. The examples may then
be opened from the folder named ‘...\MIKE Zero Projects\MIKE_HYDRO\’.
User settings
The ‘User Settings’ dialogue contains general settings for MIKE Zero. For
more details see ‘MIKE Zero User Guide’.
The tab MIKE HYDRO relates specifically to MIKE HYDRO and here it is possible to control if the setup wizard should be displayed when creating a new
setup see section 2.1 How to Start MIKE HYDRO (p. 17).
The MIKE HYDRO tab also controls the language used in the dialogue windows.
2.4.2
Edit menu
For Undo and Redo options, see .
The other options are part of the MIKE Zero framework see ‘MIKE Zero User
Guide’ for more details.
2.4.3
View menu
The menus Project Explorer, Project Map, Start Page, Simulation History and
Toolbar are all part of the MIKE Zero framework see ‘MIKE Zero User Guide’
for more details.
Load layout
The layout controls the position of all windows. Here it is possible to load a
MIKE HYDRO layout saved from another project.
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MIKE HYDRO - © DHI
MIKE Zero Menu Bar
Save layout
The layout controls the position of all windows in MIKE HYDRO. The layout is
automatically saved with the current setup, however here it is possible to
save the layout to be used in another project.
Set as default layout
Use this option to define a personal default layout for MIKE HYDRO.
Restore layout
This menu will reset the position of all windows to the default layout.
Load symbology
Load symbology settings from a symbology file (*.mhsym).
Save symbology
Save the current symbology settings to a symbology file (*.mhsym).
Reset symbology
Resets symbology settings to the default settings.
Set as default symbology
Option for creating user-defined default symbology settings.
Reset default symbology
Restore the symbology settings to the original as provided in the MIKE
HYDRO installation
Export graphics
Option for saving MIKE HYDRO graphics to either Clipboard or graphics file.
Property view: show selected
Specify whether the property view should present all data of the selected data
object or only selected data. A checkmark in front of this item states that only
Selected objects are presented.
Show or hide features and windows
The visualisation of some of the views and menu bars can be switched on or
off in the list of items presented below the ‘Toolbar...’. Click on the different
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Working With MIKE HYDRO
items to show or hide the specific item in MIKE HYDRO. If the item is visible a
Checkmark is presented in front of the item on the View list.
2.4.4
Run
The Run menu contains options for calculation, validation and simulation of
model components.
Recalculate flow conditions
This option is only available in River mode.
Extended validation
Before running the model, it is recommended to run an extended validation of
the model setup. Any validation issues will be shown in the Validation window
see section Validation (p. 25).
Simulation
To execute the model engine, select ‘Simulation’. Output from the computational engine (status and error messages) are shown in the Simulation window see section Simulation (p. 25).
2.4.5
Tools
The Tools menu contains different tools for creating and editing the setup
objects. For details on the individually tools see section 15 Main menu bar
features (p. 171).
2.5
Creating Input Files
Most data is saved within the MIKE HYDRO file, but some input data is stored
in external files. Input files will typical consist of time series saved in dfs0 files
see section 2.5.1 Create a new dfs0 file (p. 35) for more details.
Where a link to an external file must be created a button with 3 dots is shown.
Clicking on the button will show a sub-menu see Figure 2.4.
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MIKE HYDRO - © DHI
Creating Input Files
Figure 2.4
Buttons used for input files
The general functionality of the external file buttons has the options:



Browse: Allows you to browse for an existing file.
Create: Will create a file with default settings and automatically open the
file for editing with the corresponding editor.
Edit: Will open the file for editing with the corresponding editor.
For files that can be shown on a graph it will also be possible to plot the input
file to the Time Series window.
2.5.1
Create a new dfs0 file
When creating a new dfs0 file using the button for external files, a dialogue
window will be opened. This dialogue is used in different situations for creating a time series (dfs0) file or a table file. The model automatically detects the
type of file needed and adjusts the dialogue accordingly.
Create a new time series file
To create a new time series file, the following properties must be specified:




Filename: You may either browse for or manually type the name and
location of the time series file.
Period: You may choose the start and end date of the time series using
the date-time pickers. The default values will be the simulation period for
your setup.
Time axis type: You may choose among non-equidistant calendar axis
type and equidistant calendar axis type. For the non-equidistant type, the
interval between data values may vary. For the equidistant type, equal
time spacing between each time step will be enforced.
Time series interval: The time series interval is the size of the time step.
Example: Specifying the following:
–
–
–
Start date: 01-01-1980
End date: 31-12-1981
Time series interval: 1 month
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Working With MIKE HYDRO
will cause a time series file with 12 time steps to be created.




Items: Depending on the context in which the file is being created, the
file will be created with one or more data items.
Item name: The name of the data item
Uniform value: All the time series files which are created with this dialogue will contain the value specified here in all time steps (uniform
value). To create files with values varying over time (non-uniform), first
create a uniform value time series and then edit it in the time series editor.
Time series type: Contains information on how the data values are
interpreted. The possible types are:
–
Instantaneous: Means that the values are representative at one
precise instant. For example, a measured water level is an instantaneous value. Linear variation between time steps is assumed.
–
Accumulated: Means that the values are representative of one successive accumulation over time from the start of the event (start time
specified) to the current time step (.i.e. accumulated over the entire
series). For example, the rainfall is accumulated over the year if we
have recorded monthly rainfall values. Linear variation between time
steps is assumed.
–
Step Accumulated: Means values are representative of an accumulation over a time step. For example, rainfall is a step-accumulated value if the rain depth is recorded at different intervals. Values
represent the time span between the previous time step and the current time step.
Example: Rainfall measurement is started at 10:00:00. At 11:00:00
someone picks the recipient, registers the value of 10 mm and empties the recipient. At 12:00:00 the same process is repeated but with
a value of 15 mm and so on. Thus, the time series will have the
value of 10 mm at time step 11:00:00 and the value 15 mm at
12:00:00 etc.
36
–
Mean step accumulated: Means that values are representative of
an average accumulation per time step. For example, the average
rain rate is a mean step accumulated value. Values represent the
time span between the previous time step and the current time step.
–
Reverse mean step accumulated: Is equal to Mean Step Accumulated type, but values represent the time span between the current
time step and the next time step. Used for forecasting purposes.
MIKE HYDRO - © DHI
Viewing Results


Item type: The type of data item. The drop-down list can be used to
choose one of the possible item types. The choices available will depend
on the context.
Item Unit: The unit type of the data item. The drop-down list can be used
to choose one of the possible unit types. The choices available will
depend on the item type.
Note: For more information on time serie types, item types and units see the
‘DFS File User Guide’ in the MIKE Zero Documentation.
Create a new table file
To create a new table file the following properties must be specified:









Filename: You may either browse for or manually type the name and
location of the time series file.
No. of timesteps: This defines the number of rows in the table (or the
number of x-axis points on a curve).
X-axis unit: The x-axis unit can be selected from the drop-down menu.
Items: Depending on the context in which the file is being created, the
file will be created with one or more data items.
Item name: The name of the data item.
Values: Here the pair-wise values of the x-axis and the item are entered.
The table file can consecutively be edited in the time series editor.
Value series type: Contains information on how the data values are
interpreted. The possible types are the same as for a dfs0 file see section Create a new time series file (p. 35).
Item type: The type of data item. The drop-down list can be used to
choose one of the possible item types. The choices available will depend
on the context.
Item Unit: The unit type of the data item. The drop-down list can be used
to choose one of the possible unit types. The choices available will
depend on the item type.
Note: For more information on time serie types, item types and units see the
‘DFS File User Guide’ in the MIKE Zero Documentation.
2.6
Viewing Results
Results are viewed from the Result tab in the Tree view. It is possible to select
results either from a list in the Property view or from the Map view. The results
are viewed in the Time Series window see section Time series (p. 26).
Result files and other time series are controlled from the Tree view. After a
simulation the results are automatically added to the Tree view. Results from
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Working With MIKE HYDRO
previous simulations, input files or measured data (dfs0 files) can be loaded
through the ‘Add file...’ button for comparison or calibration.
Files shown in the tree are automatically linked to the setup e.g. when reopening the setup the same files will be available in the Result tree. If a setup
contains links to files that are deleted or moved the link will automatically be
removed. It is possible to manually remove the link to a file by right-clicking
on the file name and choose ‘Remove’.
2.6.1
Basin result files
The output from a basin simulation is automatically loaded to the result view.
However if results from a previous simulation should be loaded for comparison the corresponding mdh file should be chosen as this will load all related
data.
Note: The result file from a rainfall runoff simulation not including a basin simulation is a dfs0 file which must be loaded manually using the ‘Add file’ button. See section 2.6.2 Dfs0 files (p. 38).
The Tree view will display 3 nodes for ‘Nodes’, ‘Reaches’ and ‘Catchments’.
When selecting a node in the tree the related time series are shown in the
Property view. The Property view is grouped by the model object identifier
with the name in parenthesis. Expanding an identifier will show all result
types related to that model object.
Right-clicking in the Property view shows a menu for either adding the result
to a new plot or the current plot.
Selecting in the Property view highlights the model object on the map.
Selecting a model object in the Map view automatically selects the related
time series in the Property view. Right-clicking on a model object gives
access to the menu ‘Result to plot’ where results can be plotted either on a
new plot or the current plot.
Note: It is only possible to select results in the Map view, if the Map ribbon is
active and set to ‘Pan’.
2.6.2
Dfs0 files
Dfs0 files can be used for input, output and measured time series. Dfs0 files
does not contain information about the network and is therefore not connected to the Map view.
When adding a dfs0 file the Property view is automatically filled with a list of
all time series available in the dfs0 file. A filter based on the item type is
shown at the top of the Property view.
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Getting Help
2.7
Getting Help
Online help is available in all dialogues of MIKE HYDRO. The online help
system utilises the Microsoft help technology known as HTML Help.
The online help can be accessed in two ways:


Through the menu Help and choosing ‘Help Topics’
By pressing F1 in any dialogue window, which automatically will direct
you to the relevant section of the online help.
Note: In some cases the dialogue box/window must be activated (e.g. by
clicking in a cell) to ensure correct links to the online help.
2.8
Examples
A useful way to quickly get started with MIKE HYDRO is to open the examples that are included in the installation.
To install the examples go to the File drop-down menu, select ‘Options’ and
click ‘Install Examples…’. In the pop-up menu, select MIKE_HYDRO and
click ‘Install’. The examples may then be opened from the folder named
‘...\MIKE Zero Projects\MIKE_HYDRO\’
2.8.1
Basin module examples
This section includes a brief overview of the Basin Modules examples
included in the MIKE HYDRO Installation.
Demo
This example can be viewed and executed with a demo license of MIKE
HYDRO. In the getting started section, steps are described to build a similar
setup.
IrrigationFAO
This model shows an example of how to investigate the outcomes of different
irrigation strategies in a field where different crops are cultivated.
The model includes three different crops: tree, tobacco and potatoes. The
scope of such a model is to find the optimal irrigation strategy, which allows to
obtain the maximum yield from each crop without spill of water and without
incurring in water deficits.
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Working With MIKE HYDRO
Different irrigation strategies can be formulated by changing the trigger and
application options for the crops, in particular the parameters TAW and RAW.
This is done in the section Irrigation data  Irrigation method. The new irrigation methods should then be applied to the crops in the Water user  Irrigated Field section.
By changing these parameters, different irrigation scenarios can be run. A
comparison of the results from the different simulations can be made to investigate how the different crops are affected by crop stress and in which scenario the maximum yield is achieved.
IrrigationRice
This model shows an example of rice crop irrigation. The model includes an
irrigated field with three different rice crop shifts occurring during the year.
One of the applications of such a model is to investigate how the soil type
properties affect the crop yield when growing rice. Different soils types have
different effects on percolation. For example, a sandy soil allows a larger
amount of water to infiltrate, if compared to a clay soil, which has a higher
hydraulic conductivity, thus offering a higher resistance to infiltration. Deep
percolation is responsible for a part of the water losses and can therefore
deeply affect the water demand of the rice crop.
Different scenarios can be set up by changing the soil models. This is done in
the section Irrigation data  Soil and runoff. The key soil parameters to be
varied are the three soil moisture content parameters and the saturated drainage coefficient. The different soils properties can then be assigned to the rice
field in the section Water user  Irrigated Field.
After running the models with different soil types, it is interesting to investigate how the irrigation demand varies when the field has different soil properties. The differences in percolation loss between the different simulation
results can also be compared.
Other factors also affect the irrigation demand on the rice field. As done in
Example 2, different irrigation strategies can be formulated by changing the
trigger and application options for the crops, in particular the parameters TAW
and RAW. This is done in the section Irrigation data  Irrigation method. The
new irrigation methods should then be applied to the crops in the Water user
 Irrigated Field section.
WhiteNile
This example is a model of the White Nile river basin. It shows a more comprehensive river basin model as well as the utilisation of a coordinate system
and background map.
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Examples
Demo_Aqua-Republica
This setup is a water resources model included in the installation with the
overall intension for illustrating the possibility for using a MIKE HYDRO Basin
model in connection with Serious Gaming for which DHI has developed the
‘Aqua Republica’.
The demonstration example includes a setup with 3 water users, 3 reservoirs
and a number of catchments along river branches, and the setup forms the
backbone of the demonstration model that can be accessed through the
Aqua Republica webpage names as the ‘Danida version’.
Additional information on Aqua Republica is available on
THE ACADEMY by DHI’s homepage: http://theacademybydhi.com and on
the Aqua Republica homepage: http://aquarepublica.com/.
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Working With MIKE HYDRO
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Setting up a Simple Basin Model
3
Tutorial: Setting Up a Simple Model
The current chapter includes a short description on how to operate MIKE
HYDRO to set up simple examples of the Basin Module.
Setting up a Simple Basin Model
3.1
Setting up a Simple Basin Model
This short tutorial summarises the steps needed to set up a simple model (the
demo example) in the Basin module.
3.1.1
Create a new document
To create a new document, start MIKE Zero and choose the MIKE HYDRO
model document type from the MIKE HYDRO group.
Figure 3.1
Create new MIKE HYDRO document
Press the ‘OK’ button and an empty document will be created and the setup
wizard will automatically open.
3.1.2
Define simulation specifications
The setup wizard guides you through the following simulation specifications:

Modes

Description

Coordinate System

Background Map
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Tutorial: Setting Up a Simple Model

Digital Elevation Model (DEM)

Working Area
The Simulation specifications may subsequently be edited by navigating to
the relevant sections in the Setup tree view and editing the specifications/properties in the Tabular view or the Property view.
3.1.3
Create the River network
The Branches segments of a river network including associated River nodes
and Branch connections can be created in three different ways:

Method 1: Digitising a River network

Method 2: Importing a River network

Method 3: Derive the River network from a DEM
For more information see User Guide section 6.1 Creating a River Network
(p. 61).
When the Branch has been completed, the properties can be inspected and
edited in the Tabular view or the Property view.
3.1.4
Create a Catchment
In the demo example, the Catchment is a schematic catchment, i.e. the
catchment is represented by a default shape. To create a schematic catchment, see User Guide section Creating a catchment (p. 75).
When the catchment has been created, the catchment properties must be
specified in the Catchments Tabular view or the Property view (see User
Guide section 7.1 Catchment definitions (p. 77)). A runoff time series must be
provided. All runoff from the catchment is added to the River network in the
Catchment node.
3.1.5
Insert a Reservoir
To insert a Reservoir, see User Guide section Inserting a reservoir (p. 127).
When the Reservoir has been added, the reservoir properties must be specified in the reservoirs Tabular view or the Property view (cf. User Guide section Specifying reservoir properties (p. 127)).
3.1.6
Insert two Water users
To insert a Water user, see User Guide section Inserting a water user
(p. 102).
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Setting up a Simple Basin Model
Note that the location is for visual purposes only and has no impact on the
model setup.
When the Water user and the associated supply and return flow Connections
have been added, their properties must be specified in the Water users Tabular view or in the Property view (cf. User Guide Specifying water user properties (p. 102)).
3.1.7
Insert a Hydropower plant
To insert a Hydropower plant, see User Guide section Inserting a hydropower
plant (p. 147).
When the Hydropower plant and the associated supply and return flow connections have been added, their properties must be specified in the Hydropower plant Tabular view or in the Property view (cf. User Guide Specifying
hydropower properties (p. 148)).
3.1.8
Validate the setup
The initial validation status of the model setup is indicated in the Setup tree
view. If a green tick mark is displayed on the tree node, the group of setup
parameters is valid. In case of errors, a red cross is displayed in the tree node
and an error message is displayed in the Validation window.
Note: A validation tick mark is only displayed if the model setup parameter
node has been opened.
Before running the model, it is recommended to run an extended validation of
the model setup. This is done by selecting ‘Extended validation’ in the ‘Run’
drop down menu in the MIKE Zero menu bar. Any validation issues will be
shown in the Validation window.
3.1.9
Running a simulation
To execute the model engine, select ‘Simulation’ in the ‘Run’ drop down menu
in the MIKE Zero menu bar. Output from the computational engine (status
and error messages) are shown in the Simulation window.
3.1.10 Inspecting the results
When the simulation has been run, the results may be viewed in the Time
series window. To add an output time series to the window, navigate to the
relevant model parameter group in Results tree view, right click on the relevant object in the Property view and select the time series to be added to a
new/current plot in the Time series window.
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Tutorial: Setting Up a Simple Model
Alternatively, output time series may be added to the Output window by right
clicking on the relevant object in the Map view, selecting ‘Result to plot’ and
select the time series to be added to a new/current plot in the Time series
window.
From the Boundary ribbon in Map view, select ‘Add’ and create new boundary
conditions at the upstream and downstream point of ‘Main’ and upstream end
of ‘Tributary’ by locating the cursor on these locations and make a single
mouse click. Change to Tabular view for additional boundaries details specification.
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Modes
4
Simulation Specifications
The Simulation specifications includes the more overall control settings for
model simulations such as; which sub-modules are included in the simulation, which simulation period and time step are to be applied and additionally,
overall control parameters for the simulation performance are included.
The following pages are included for defining Simulation specification for
each model type:
4.1
Modes
The first action to take in a MIKE HYDRO project definition is to specify
whether the actual project is a Basin model or a River model. This selection is
made in the upper drop down selection box. From this box, choose either
‘Basin’ or ‘River’ to activate one of these model types.
The content of the tree view in the GUI depends on the overall module selection as different features are available for the Basin and the River models
respectively. Additionally, the content and appearance of the Modules page
depends on the choice of ‘Model type’.
Following the selection of ‘Model type’ there are a number of options for
selecting additional features through activation of Model specific modules
and global settings for the specific project (see Figure 4.1).
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Simulation Specifications
Figure 4.1
Model type and Module selection page for MIKE HYDRO Basin.
The ‘Modules’ section of this page contains two rows of checkboxes. These
can be activated and deactivated by the user depending on the preferred GUI
appearance and requirement for the project simulations.
The checkbox functionality are as follows:


‘Data’ :
Controls whether the data related to the specific module or feature are
visible in the tree view.
Enable the specific ‘Data’ checkbox for all features that you want be visible and editable from the GUI tree view.
Important Notice: The Data checkbox activation does not enable a feature for simulation.
‘Sim.’ :Control
Controls whether the specific module is active in the simulation or not.
‘Sim.’ checkbox must be enabled to include the feature in the simulation.
Note: It is not possible to activate a ‘Sim’ checkbox if the equivalent
‘Data’ checkbox is no active as well.
All ‘Sim’ checkboxes are per default acitve
Module options are described in details in following sections.
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Modes
4.1.1
Basin modules
The Basin modules includes specification of Basin specific features and
Global parameters for the project:. Options are:

Basin modules:
–
–
–
–
–
–

Rainfall runoff
Basin simulation:
Include groundwater (add-on for Basin Simulation)
Include reservoir sedimentation (add-on for Basin Simulation)
Water quality (add-on for Basin Simulation)
Use global ranking (add-on for Basin Simulation)
Global parameters
–
–
Unlimited resources in catchments without groundwater model
Subtract area of irrigation users and reservoirs from catchment area
to calculate runoff
Rainfall runoff
Optionally, rainfall-runoff modelling can be included in the Basin model.
Inclusion of Rainfall runoff in a simulation requires that one or more Catchments are defined in the Basin model. Runoff from catchments to river nodes
can then either be included through the use of fixed runoff time series files for
individual catchments or by activating the calculation of runoff from Catchment characteristics and precipitation (rainfall).
Two types of rainfall-runoff models are available:


NAM:
A lumped, conceptual rainfall-runoff model, simulating the overland flow,
interflow, and baseflow components as a function of the moisture contents in four storages.
UHM:
The Unit Hydrograph Model includes different loss models (constant,
proportional) and the SCS method for estimating storm runoff.
The type of model and associated required input data are specified in Catchment definitions page (cf. Section 7.1.3).
Basin simulation
Basin simulation includes the options for calculating a large variety of different processes and model components taking part in the water consumption
and influencing the water balance with a river basin. Basin simulation utilise
the calculation engine from DHI’s predecessor to MIKE HYDRO for water
resources management simulations; MIKE BASIN, and most of the calcula-
49
Simulation Specifications
tion methods for specific modelling features are therefore mature and validated through intensive project applications over a large period of time.
Include groundwater
Optionally, groundwater processes can be included in Basin module. The
underlying conceptual model is the linear reservoir model concept (see
Appendix A.1 The Linear Reservoir model) with one or two aquifers (fast/slow
response).
The conceptual structure of the two-layer groundwater component is illustrated in Figure 4.2. Single-layer models only include the shallow (upper)
aquifer.
Figure 4.2
Conceptual structure of the groundwater component
As illustrated in Figure 4.2 groundwater interacts with the surface water via
groundwater recharge, groundwater discharge and seepage from rivers, reservoirs and connections. Moreover, when the water table of the shallow
(upper) aquifer reaches the land-surface, it starts to spill directly into the river.
Finally, groundwater from the deep aquifer can be pumped by water users.
Include reservoir sedimentation
The reservoir sedimentation module routes sediment through the river network and calculates the potential deposits of sediment in the Reservoirs. The
reservoir sedimentation module is not a sediment transport model. Sediment
is supplied by catchments and is routed through the river network under the
assumption that no erosion takes place and deposition solely occurs in the
Reservoirs. Any sediment not deposited in the Reservoir is routed to the river
downstream and to users supplied by the Reservoir. Sediment is distributed
according to the discharge distribution.
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Description
Water quality
The Water quality (WQ) module is based on ECO Lab, which is a highly flexible framework for defining water quality models. ECO Lab utilise a concept of
templates where water quality models are defined with equations and variables, and the water quality option therefore, allows the usage of different
water quality models/templates depending on the issue of concern. MIKE
HYDRO Basin installation includes two predefined water quality templates
that can be applied as is - or can be adjusted by the user to conform with the
specific project requirements.
Use global ranking
Global ranking may be used to prioritise water allocation to Water users,
Hydropower plants and Reservoirs independently of their geographical location in the river basin. When global ranking is selected, all other allocation
rules/priorities are ignored. This includes local priorities and Reservoir reduction levels.
Global parameters
The Global parameters defines global characteristics in the model framework
which will be globally applied (for all relevant features).
Unlimited resources in catchments without groundwater model
If this parameter is enabled, groundwater in Catchments without a groundwater model is assumed to be an unlimited resource with no feedback to the surface water system. If it is disabled, no groundwater is available in Catchments
without groundwater model.
Subtract area of irrigation users and reservoirs from catchment area to
calculate runoff
If this module/parameter is enabled, the area of irrigation users and reservoirs is subtracted from the catchment area prior to calculating catchment
runoff. This is particularly important if irrigation users and/or reservoirs have
significant surface areas compared to the catchment area, in which they are
located.
4.2
Description
The Description dialogue includes the option for supplying a user specified
Title and a Description for the simulation and the project in general.
Every simulation should be given a Title. Except from helping to describe the
actual simulation performed the title will also be included as part of the default
name for result files defined by MIKE HYDRO (see section 14.1 Standard
Results (p. 169)).
Note: Simulation results with a title already used will overwrite the existing
results unless a new result folder/file has been specified.
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Simulation Specifications
4.3
Simulation Period
The simulation period is generally defined by specifying the required Simulation start date and time and Simulation end date and time.
Date and time can be edited manually by clicking the start date or end date
field and change the date (Year+Month+Day) and time (hour+minutes+seconds). In this case it is possible to use the right and left arrow keys to navigate between the date and time variables.
Alternatively, dates can be selected using the calendar icon;
, which will
open a calendar that allows to browse for the required date (see Figure 4.3).
Note, that the simulation time will still have to entered manually after choosing a date from the calendar date selection.
Figure 4.3
Calendar date selection option for simulation periods
Note that it is possible to use input time series for model input parameters,
which have different length than the simulation period, and different temporal
resolution than the simulation time step.
If an input time series does not cover the entire simulation period it must
cover a period of at least one calendar year when the simulation period is
longer than a year. If an input time series covers exactly one year it will be
recycled using the appropriate values for the simulation period, both for the
period
If the input time series is longer than a year, input data from the first full year
will be used for the simulation period before data exist, and input data from
the last full year will be used for the simulation period after data exists.
The `Apply default' button can be used to extract the possible simulation
start-time and end-time. Once the button is activated a search of time-intervals in all time series files included in the actual simulation takes place and
the earliest possible start-date and latest possible end-date is automatically
transferred to the date-fields.
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Time Step Control
Note: If no dates are proposed from activating the button the most likely reason will be that there are no overlapping time series in the setup.
4.4
Time Step Control
Time step control features includes options for defining simulation period and
time step amongst other parameters for the different modules.
River basin management
Any constant time step can be used in the simulation. Note that the temporal
resolution of the input time series can be with any variable temporal resolution different from the simulation time step. Depending on the value type of
the time series different interpolation method is used. For more details, see
2.5 Creating Input Files (p. 34).
Note that if the monthly time step is selected, the time step length must be
one month, i.e. it is not possible to select a 2 or 3-month time steps.
The results will be written for every time step. However in order to reduce the
size of the result file without compromising the accuracy of the computation it
is possible to choose a time step sub multiplier. Each time step will be divided
by equal sub time step for computing the results, however the results will be
written at the end of every time step. For example, if the time step is 1 day,
and the time step multiplier is 4, then the computation will be performed every
6 hours, and the results will be written daily.
It is possible to run a simulation with the Basin module in a simple stochastic
type of mode, where the initial conditions are reset every year. This is convenient if you want to analyse e.g. drought management scenario for a number of months in the future for likely climatic/inflow conditions. Running in the
stochastic mode for say a 20 years period, a 20 years output file of e.g. water
level will be produced. It can be interpreted as running 20 times one-year
simulations using the same initial condition, but for different inflows and climatic conditions.
If reservoir sedimentation is included in the Basin simulation (cf. Section
4.1.1), the frequency at which the level area volume (LAV) curve is updated
(number of time steps between updates) must be specified.
Rainfall runoff time step length
If Rainfall-runoff has been enabled in the Modules part of Simulation specification (cf. Section 4.1.1), the time step length to be used by the Rainfall-runoff model must be specified.
53
Simulation Specifications
4.5
Computational Control Parameters
Computational Control Parameters includes options for specifying parameter
values for variables used to control the behaviour of the computational engine
within MIKE HYDRO.
Computational control parameters are used in the Basin simulation as criteria
for solving the water quantity distribution.
The calculation of the flow in the river network for each time step requires an
iterative procedure. The computation of the time step will finish when the convergence criteria have been reached. A convergence criterion is given for the
flow on the branches and one for the remote flow control nodes. A maximum
number of iterations is defined to ensure that each time step will be completed within an acceptable amount of time. The default value is 150 iterations. A warning message will be issued when the computation of the time
step cannot be achieved successfully within the maximum number of time
steps.



54
Maximum number of iterations. Maximum number of iterations in solving water quantity distribution. This corresponds to the maximum number
each time step will be computed. This number will affect the computation
time of Basin simulation. Please note that every time step is computed
by at least 4 iterations.
Flow convergence criteria. Maximum change allowed in flow at each
computation node between two successive iterations.
Control flow convergence criteria. Maximum difference allowed in flow
between the calculated and target flow at remote flow control nodes. This
parameter applies for both maximum and minimum remote control flow
rules.
MIKE HYDRO - © DHI
Coordinate System
5
Map Configurations
The Map view is the focal point of each MIKE HYDRO model session, and
the Map configurations option enables a user-defined customisation of the
Map view appearance to best suit the user’s preferences and requirements.
Map configurations include the options:
5.1

Coordinate System (Map view and Feature coordinate systems)

Background Map (Map view background)

Background layers (Shapefile, raster, and image definitions)

Digital Elevation Model (DEM) (Background and processing)

Working Area (Map view working area definition)
Coordinate System
The user can select a coordinate system for the Map view in the Setup tree
view. The Map view coordinate system is selected using the drop-down menu
labeled “Map view coordinate system”.
If the user would like for features of the model (i.e., branches, water users,
catchments, etc.) to use a different coordinate system than the Map view
coordinate system, then it is possible to select a different coordinate system
using the drop-down menu labelled “Coordinate system for features stored in
setup file”.
If two different coordinate systems are selected, the coordinates of the model
features are automatically converted into the map coordinate system when
displayed in the Map view. However, model features are saved in the model
feature coordinate system.
In some cases, the coordinate system used for model features may be based
on a different datum than the datum used in the Map view coordinate system.
In these cases, a datum shift can be applied to locate model features correctly in the Map view. Two approaches are available: a three-parameter
Molodensky transformation, and a seven-parameter 3D Helmert transformation. Details of the two approaches are documented in the geodesy manual
supplied with the installation (MIKE_Zero_Geodesy.pdf).
See also: http://www.arcwebservices.com/arcwebonline/services/dattrans.htm.
A different coordinate system for model features should be considered if the
study area is located in an area where distances are distorted significantly in
the Map view coordinate system. For example, using a Sphere Mercator
coordinate system in the north of Alaska would result in significant errors in
calculated river reach lengths.
55
Map Configurations
If the model working area is located in a region where the risk of significant
errors due to distortion is large, the user will receive a validation warning. Validation messages will not be issued unless a working area has been defined.
5.2
Background Map
A background map can be selected in the Setup tree view. Three options are
available: None, a Google map background, and a Countries/Coastline
shapefile. If the Google map background is selected, the user is prompted to
select from a drop-down list of available map types. Both the Google map
and Countries/Coastline shapefile can be disabled in the Map view by
unchecking the Visible check box.
Note: In order to use Google map background, an internet connection must
be available. Google maps images are automatically rectified to the Map view
coordinate system.
5.3
Background Layers
Background layers including shape files, images, and rasters can be added in
the Setup tree view. To add a new background layer, click on the
icon and
select the layer type.
Image area coordinates can be read from a world file or else specified by the
user. If using a world file, the world file must be located in the same directory
as the image file, with the same name. Otherwise, image coordinates can be
entered by hand.
Shape file background layers require specification of a projection type. If a
projection file (PRJ file) exists, the projection type is automatically read. Otherwise, a user-specified map projection must be selected.
The raster background layer is used when the user would like to use a digital
elevation model (DEM) or other raster as a background layer in the Map view.
Procedures for adding raster background layers are identical to the procedures for adding a DEM (described in the next section). The raster background layer should be used to add a DEM as a background if the user would
like to view a DEM together with other background layers.
Background layers are displayed in the Map view in the order given in the list
of layers found at the bottom of the tabular view (when Background layers is
selected in the Setup tree view). The appearance of background layers follows the order in the list of images (i.e. the image in line 1 is on top, then
image 2 is below image 1, then image 3 is below image 2, etc.). It is possible
to rearrange the order of images by selecting an image and using the arrows
to move the selected image up or down in the list.
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Digital Elevation Model (DEM)
Display settings for background layers can be modified in the Symbology tree
view. In this view, layer transparency settings can be changed so that underlying background layers are visible in the Map view. It is also possible to
remove layers from the map view by unchecking the Visible box. Other
aspects of symbology can also be modified, such as colour schemes and feature labels. For more details about symbology options, please see the discussion of symbology in Section 2 (Working With MIKE HYDRO).
5.4
Digital Elevation Model (DEM)
A Digital Elevation Model (DEM) may be included in the model setup for river
tracing and catchment delineation.
A DEM can be defined in two file formats, either as a ESRI ASCII or a dfs2
file. For ESRI ASCII files the coordinate system and z unit for the file must be
specified. If a dfs2 is chosen, these parameters are taken from the dfs2 file
definitions.
The DEM can be viewed together with the other background layers in the
Map view. However, the DEM is always placed above the other background
layers. Therefore, if the user would like to view the DEM together with other
background layers, it is recommended to also load the DEM as a raster background layer (described in the previous section). The DEM can be removed
from the Map view by unchecking the Visible check box in the Symbology
tree view.
The colour scheme used for the DEM can also be modified in the Symbology
tree view.
5.4.1
River tracing and catchment delineation
If the checkbox, ‘Use DEM for river tracing and catchment delineation’ is
selected, the DEM can be used to delineate rivers and catchments based on
the elevations in the DEM. Delineation is carried out using the ‘Add trace’ and
‘Add delineate’ tools in ‘Branch’ and ‘Catchment’ ribbons. More details about
these tools are available in Section 6 (River Network) and Section 7 (Catchments). Before these tools can be used, however, the DEM must be processed.
Processing elevation data
The DEM is preprocessed to create a raster file with flow direction information
that is used to delineate river branches and catchments.
Note: It is recommended that the size of the DEM should not exceed 25 million pixels. A warning message will be shown if the size of the DEM is above
this limit.
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Map Configurations
The size of the DEM can be reduced by changing the spatial extent or by resampling.
Spatial extent
The spatial extent of the DEM can be limited to the defined working area (see
below), thereby reducing the number of pixels.
Resampling
Resampling requires specification of a resampling factor. If a resampling factor of 2 is used, then the minimum elevation of a 2x2 set of pixels is assigned
to one new pixel with the same area as the 2x2 set. A resampling factor of 3
assigns the minimum value of a 3x3 pixel set to one new pixel with the same
area as the 3x3 set.
Preprocess digital elevation data
In order to use the river tracing and catchment delineation on the map, the
digital elevation data must be preprocessed by clicking the button ‘Preprocess digital elevation data’. After changing the spatial extent or resampling the
elevation data, the DEM must be preprocessed again.
The processed data is saved in a ppdd-file. If no location is specified, then the
ppdd file is saved by default in the same location as the model setup.
Many DEMs contain inaccuracies because of their resolution or artifacts
resulting from the method of creation. When delineating catchments and rivers from the DEM, you may find some unexpected results. This can happen
in flat areas where DEMs may not have the vertical resolution to correctly
delineate the rivers and catchments.
Note: In many digital elevation models, all pixels in lakes have undefined (or
blank) pixel values.
If the option ‘Assume internal undefined areas as local depressions’ is set, all
internal undefined areas are handled as a local depression. When a traced
branch is added, an artificial channel will be traced through the depression
along the shortest path between the upstream and downstream ends. For
example, if a lake is represented in a DEM as an undefined area, then an artificial flow path will be created through the lake along the shortest path to the
outlet.
If undefined areas are not set as local depressions, a traced branch will stop
upon reaching an undefined area.
5.5
Working Area
A working area may be defined by clicking ‘Draw rectangle on the map’ and
dragging a rectangle on the map. Once defined, the working area may be
edited (and edits must be saved) but it cannot be deleted.
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Working Area
If no working area is defined, the maximum extent of features is used as
default working area.
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Map Configurations
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Creating a River Network
6
River Network
The River network forms the basis of all Basin applications. The river network is defined as a combination of connected river segments and computational nodes , and module specific features are then generally added to the
model using the river network as a base (river network example illustrated in
Figure 6.1)
Figure 6.1
Example of river network in MIKE HYDRO.
Additional river network details:


Computational points comprise a number of different features for which
points are inserted in the network when these are defined (e.g. catchment nodes for catchment inflow and river nodes where branches are
connected.
Inflow to the River network is provided by Catchments (see Catchments).
This chapter describes the following topics in further detail:

6.1
Priority Nodes
Creating a River Network
The Branches segments of a River network including associated River nodes
and Branch connections can be created in three different ways:

Method 1: Digitising a River network

Method 2: Importing a River network
61
River Network

Method 3: Derive the River network from a DEM
In either way, it is recommended to reference your network geographically, so
that features are located at their correct geographical coordinates (cf. Section
5.1 Coordinate System (p. 55)).
6.1.1
Method 1: Digitising a River network
For schematic models and small river networks, the network can be digitised
directly on the map. A background map (cf. Section 5.2 Background Map
(p. 56)) can be selected to assist when digitising.
Figure 6.2
Add Branches and Branch Connections
To digitise a Branch, go to Map view, select the Branches ribbon and click on
the ‘Add’ button. Use the left mouse button and click at each point along the
river. To finish the Branch, double-click on the last point.
To edit the shape of an existing branch click on the ‘Edit Branch’ button and
click on the branch to be edited. All points on the branch are shown with a
small square. To add a new point click on branch at the location of the new
point. To move an existing point click on the square and drag to the new location. To remove an existing point double-click on the point.
Branches may be connected by using the ‘Add/Edit Branch Connection’ button.
Note that the snap distance has been hard-coded as 5 pixels.
The Basin module requires that Branches and Connections are always digitise from upstream to downstream.
If you make a mistake while you are still digitising you can use the Esc button
to cancel the operation.
6.1.2
Method 2: Importing a River network
The River network may be imported from an existing shape file by selecting
‘Import’ in the File drop-down menu and clicking in ‘Network from shape file’.
This opens the ‘Import Branches’ dialogue.
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Branches
Click on the
button and browse to the existing shape file. Branches
can be auto-connected by enabling ‘Auto connect branches’ and specifying a
maximum distance for auto-connection.
Note: Existing MIKE 11 models can be imported by selecting ‘Import’ in the
File drop-down menu and clicking in ‘Network from MIKE 11’.
6.1.3
Method 3: Derive the River network from a DEM
A branch may be added using a DEM see Section 5.4 (Digital Elevation
Model (DEM).
When a DEM has been loaded the ‘Add trace’ button is enabled on the
Branch ribbon. Clicking on the upstream location of the river will trace down
to the outlet of the river based of the DEM data. Subsequent branches will be
traced down to the point where they flow into existing river branches.
Note: In local depressions (areas with local minimum values, e.g. lakes or flat
areas) the tool connects the ‘inflow’ and the ‘outflow’ of the depression using
an algorithm that ensures the river is traced within the depression. This line
may not represent the actual location of the river.
Moving the cursor over the map will automatically display the traced river
according to the cursor position.
6.2
Branches
The Branches properties dialogue contains the following tabs:
6.2.1

General

User defined chainage points
General
The properties of Branches are specified under the General tab. The lower
part of the dialogue window contains a list of all Branches in the River network. Select a Branch from the list and specify the properties.
Definitions
Branch name
A Branch can be given any name.
Identifier
The branch identifier is an automatically generated - and unique - parameter
string used internally in MIKE HYDRO Basin to link Basin features to specific
river branches. The identifier is a fixed, non-editable variable.
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River Network
Start chainage
The chainage of the first point in the branch. To change this chainage, it is
required to insert a User defined chainage point in the first point of a branch.
The chainage can then be specified under the User defined chainage points
tab (see below).
End chainage
The chainage of the last point in the branch. To modify this chainage, a User
defined chainage point must be inserted in this last point of the branch. The
chainage can then be specified under the User defined chainage points tab
(see below).
Connections
Information about Branches and their upstream and downstream linkages are
provided.
Edit coordinates of vertices
In some cases it might be necessary to update the coordinates on the map
view of the vertices of one or more branches.
When a specific branch is selected in the table and the “Edit coordinates of
vertices…” button is pressed, a table-dialogue pops up. This table contains
the X and Y coordinates of the points of the selected branch, which can be
edited (copy and paste is also supported). No new rows can be added, nor
deleted. When the update is done and OK is pressed, the map view is
updated.
Load shape
It is possible to import/load the shape of an existing branch directly.
Select/activate the actual branch in the tabular view and Click ‘Load shape’,
select the relevant shape file and choose the shape item that represents the
branch.
Note: this functionality will only edit the shape of the active branch on the
map. It will not create any new branch. Instead, it is possible to import and
create one or multiple branches at once from a shape file. To achieve this,
please see section Import from Shapefile.
6.2.2
User defined chainage points
A user defined chainage point is a specific location with a controlled chainage.
If a branch does not contain any user defined chainage points the start chainage is per default 0 and the end chainage equivalent to the length of the
branch calculated based on the geographical length of the branch shape.
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River Nodes
Both the start and end chainage can be controlled by inserted user defined
chainage points.
The chainage along a branch between two user defined chainage points are
linearly calculated between the two defined chainage values. The chainage
along a branch between a user defined chainage point and a branch end is
calculated is calculated as the geographical distance from the defined chainage value.
User defined chainage points are added to the River network by using the
‘Add’ button in the ‘User defined chainage point’ section under the Branches
ribbon in the Map view.
If user defined chainage points have been added in Map view their chainage
may be edited under the User defined chainage points tab.
Note: If a user defined chainage point is moved the defined chainage is fixed
and hence moving the point will update all chainages along the branch.
Example: A branch without user defined chainage values are created with a
geographical length of 1000 m. The start chainage will be 0 and the end
chainage will be 1000.
A user defined chainage point is added at 500 m (geographically) along the
branch and given the chainage 750. The start chainage is now automatically
updated to 250 and the end chainage to 1250.
Another user defined chainage point is added at 250 m (geographically)
along the branch and given the chainage 100. The start chainage is now
automatically updated to -150 and the end chainage is unchanged at 1250.
6.3
River Nodes
River nodes are automatically inserted, but may also be added manually by
using the ‘Add’ button under the River nodes ribbon in the Map view.
There are several types of River nodes in the Basin module:



Regular river nodes are inserted automatically in all confluences and
diversions (including to/from ‘Connections’).
Catchment nodes and Reservoir nodes are inserted automatically when
Catchments and Reservoirs, respectively, are added to the River network.
ReservoirCatchment nodes are inserted automatically when Reservoirs
are located on Catchment nodes.
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River Network
Other River node types are created when a regular river node is given additional properties such as Priority or Routing River nodes.
In the River nodes properties dialogue, three types of information can be
specified:

Flow loss time series

Flow capacity time series

Bifurcation type and associated data
If one or more Water users are connected to a River node, the node is automatically defined as a Priority node and additional information must be specified in the Priority node properties dialogue (cf. Section 6.4).
6.3.1
Flow loss time series
River Branches may lose water due to seepage and /or evaporation. If these
processes are considered to be of importance they may be included in the
model as a time series that specifies the losses. Flow loss is applied to the
flow leaving the river node. To model flow loss through an entire river Branch,
flow loss must be specified for all River nodes in that Branch. Both seepage
and evaporation can be specified as a fraction of the actual flow (dimensionless), or as flux (volume per time).
To add a flow loss time series, enable ‘has flow loss’ and click on the
button and click on Browse... to select an existing flow loss time series or
click on Create a new file… to open the Create a new dfs0 file dialogue.
If groundwater is defined in the Catchment where the River node is located,
seepage loss is added to this groundwater storage. Seepage loss from a
Catchment node, however, is added to the immediate downstream Catchment, if present. Otherwise, seepage flow is lost.
6.3.2
Flow capacity time series
Branches may be assigned a flow capacity [Volume per time] that can never
be exceeded (relevant for pipes and closed channels). The flow capacity is
restricting the flow leaving a River node. To model flow capacity in an entire
river Branch, flow capacity must be specified for all River nodes in that
Branch.
To add a flow capacity time series, enable ‘has flow capacity’ and click on the
button and click on Browse... to select an existing flow capacity time
series or click on Create a new file… to open the Create a new dfs0 file dialogue.
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Priority Nodes
If the flow capacity of a Branch is reached, the model will attempt to force the
water in an alternative direction. If this is not possible, the simulation will terminate with a message.
6.3.3
Bifurcation type and associated data
(Only for Bifurcation nodes).
A river Branch can be divided into maximum two downstream river Branches
at a node. Such a node is interpreted as a Bifurcation node and allows bifurcation properties to be specified.
Note that a Bifurcation node cannot be used as an extraction point.
There are two ways of specifying bifurcation:
1.
Specifying bifurcation in a Bifurcation time series file, where the flow to
the minor Branch (the diverted water) is a function of time (though limited
by the available net flow to the bifurcation node). When choosing this
option, you must supply a time series of bifurcation ‘demand’.
2.
Specifying a Bifurcation table, where the flow to the minor Branch (the
diverted water) is a function of the net flow to the Bifurcation node. When
choosing this option, you must supply a table that defines this relationship.
Note to avoid an error due to the need for extrapolation, the table should have
(0,0) as its first row and a large value in the first column of the last row
To add a Bifurcation time series or Table click on the
button and click
on Browse... to select an existing Time series/Table or click on Create a new
file… to open the Create a new dfs0 file dialogue.
Note that in order to specify properties for the minor Branch (e.g. flow loss,
flow capacity and routing) a River node must be inserted at the beginning of
the minor Branch.
6.4
Priority Nodes
A Priority node is a river node from which water is extracted to one or more
water users. Priority nodes are automatically added to the Priority nodes
properties dialogue.
In the Priority nodes properties dialogue two types of attribute data is specified:

Minimum flow

Priorities
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River Network
To specify properties for a particular Priority node, select the node from the
list of priority nodes.
6.4.1
Minimum flow
A Minimum flow time series can be specified for a Priority node. Minimum
flow is the river discharge that must be allowed to pass the node (passing
flow) before any water is extracted for Water users connected to the node. To
add a Minimum flow time series, enable Minimum flow (passing flow) at priority node; click on the
button and click Browse... to select an existing
minimum flow time series or click Create a new file… to open the ‘Create a
new file’ dialogue.
Note that the Minimum flow rule is a local rule. It is not to be used to control
the discharge in remote locations. It cannot be specified for the outlet node.
6.4.2
Priorities
When more than one Water user is connected to the Priority node, a set of
rules that defines how the available water is allocated in case of water shortage is required. Two different options are available:
1.
Supply by priority: Each of the Water users is getting their demand fulfilled in order of priority, i.e. each water user is assigned a priority and the
demands will be fulfilled according to the assigned priorities.
2.
Supply by fraction of flow: Each Water user is assigned a fraction of
the available water at the priority node. The sum of the assigned fractions must be equal to one.
If the Supply by priority rule is selected, a priority number has to be specified
for each Water user. The number 1 specifies the highest priority, the number
2 the second highest priority and so forth. By default, Water users are given a
priority according to the sequence the connections are digitised. The priority
can be changed in the priority column.
If the Supply by fraction of flow is selected, a time series file needs to be
specified for each water user. The time series must contain the fraction of the
flow to be supplied to the Water user.
It is possible to use a combination of Supply by priority rule and Supply by
fraction of flow by assigning the same priority to one or more groups of water
supply priorities and then specifying the fraction of flow required from each
water supply within the ‘shared priority’ group. The fractions for all water supplies within a ‘shared priority’ group must not exceed one at all times.
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Routing
Example
In a Priority node, water is distributed to three Water user nodes. The available flow in the river is constant equal to 10 m3/s at the river node. The three
water user nodes have the following water requirements: the City (W4)
requires 5 m3/s, and the Village (W5) and the Industry (W6) each require 4
m3/s. The following rule was specified for the Priority node:
1st priority: City,
2nd priority: Village and Industry, sharing 50/50 (described by a time series).
The simulation yields the following supply to the water user nodes:
City: 5 m3/s, Village and industry: each 2.5 m3/s.
Note that the City is not restricted, whereas the Village and the Industry both
experience an equal deficit.
6.5
Routing
In the Routing method properties dialogue, routing of flow as well as water
level calculations can be included.
Routing can be used to model the hydraulics of upstream tributaries and secondary river branches, where the main concern is to route water to the main
river system.
Routing is a simplified hydraulic calculation. Normally, simulation of hydrograph mitigation along a branch is based on the shallow water equations,
which require cross section information. However, routing doesn't require
such cross sections. The concept of routing is basically transformation of a
hydrograph, i.e. calculating the modified hydrograph (different peak value and
adjusted shape) at a given location based on the hydrograph at the upstream
point and simple parameters.
6.5.1
Routing method
Routing is assigned to a river node and applied to flow leaving that river node.
To add routing to a river node click on the append button
at the top of the
table.
Location
Then select the branch on which the river node is located and select the river
node. To enable routing through an entire river branch, routing must be specified for all river nodes in that branch.
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River Network
Flow routing method
A number of routing options are available from a selection list. The below
listed three routing options are supported by the Basin module:

Linear reservoir routing

Muskingum routing

Wave translation
Linear reservoir routing
Linear reservoir routing distributes flow leaving the river node over all time
steps. When linear reservoir routing is selected a delay parameter K (the linear routing time lag), must be specified.
Delay parameter
The delay parameter K specifies the time for the incremental flood wave to
traverse the river between the selected river node and the next downstream
node. Its value may be estimated as the observed travel time of the flood
peak between the nodes.
For a pulse inflow, outflow peaks after a specified time given by the time lag,
and then decays exponentially. The formula used is:
qo =  1 – x    dt   K    qi + x  s with x = 1 – e
 – dt  K 
(6.1)
where qo is outflow from the node, dt is time step length, qi is inflow to the
node, s is storage in the subsurface, and K is the linear routing time lag (or
delay parameter).
This algorithm includes damping. For a given time step, river storage is
updated based on the following formula:. Variables dt and K are as explained
previously, and T [-] is an intermediate result.
T = 1.0 – e
 dt
-----
 K
(6.2)
·

dt 
Volume Outflow =  1.0 – T   -----  Volume Inflow + T  Storage

K 

Storage = Volume Inflow – Volume Outflow
(6.3)
(6.4)
Note that for linear reservoir routing, river storage is a virtual quantity that can
be negative.
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Routing
Muskingum routing
When selecting Muskingum routing a delay parameter K and a shape parameter X must be specified.
Delay parameter
The K parameter specifies the time for the incremental flood wave to traverse
the river between the selected river node and the next downstream node. Its
value may also be estimated as the observed travel time of the flood peak
between the nodes.
Shape parameter
The shape parameter, X (dimensionless) depends on the shape of the modelled wedge storage. In natural rivers, X has a value between 0 (reservoirtype storage) and 0.3 with a mean value of 0.2 (X must always be less than
0.5 (full wedge storage)). Greater accuracy in determining X may not be necessary because the results are relatively insensitive to the value of this
parameter.
Note that Muskingum routing can only be used when simulation time step
length (dt) is within the following range: 2Kx < dt < 2K(1-x). If simulation time
step length is outside this range Muskingum routing becomes unstable and is
automatically replaced with linear reservoir routing. Linear reservoir routing is
a special case of Muskingum routing with shape parameter x = 0. Unlike general Muskingum routing, linear routing is defined for all combinations of time
step lengths and K values.
The Muskingum method is a commonly used hydrologic routing method for
handling a variable discharge-storage relationship. This method models the
storage volume of flooding in a river channel by a combination of wedge and
prism storage. During the advance of a flood wave, inflow exceeds outflow,
producing a wedge of storage. During the recession, outflow exceeds inflow,
resulting in a negative wedge. In addition, there is a prism of storage, which is
formed by a volume of constant cross section along the length of the prismatic channel.
Assuming that the cross-sectional area of the flood flow is directly proportional to the discharge of the section, the volume of prism storage is equal to
KQ, where K is a proportionality coefficient, and the volume of wedge storage
is equal to KX(I - Q), where X is the shape parameter. The total storage S is
therefore the sum of two components.
S = KQ + KX  I – Q 
(6.5)
This expression can be rearranged to give the storage function for the
Muskingum method:
S = K  XI +  1 – X Q 
(6.6)
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River Network
which represents a linear model for routing flow in streams.
The values of storage at time j and j+1 can be written, respectively, as
S j = K  XI j +  1 – X Q j 
(6.7)
S j + 1 = K  XIj + 1 +  1 – X Q j + 1 
(6.8)
Using equations (6.7) and (6.8), the change in storage over time interval is:
S j + 1 – S j = K  XI j + 1 +  1 – X Q j + 1  – K  XIj +  1 – X Q j 
(6.9)
Wave translation
The Wave translation algorithm basically uses a cyclical buffer with ‘slots’ for
every time step. The inflow at a time step is put into the current slot, and the
corresponding earlier inflow that was stored in that slot is pulled out. The
index of the current slot cycles within the buffer, such that a new inflow
always replaces the ‘oldest’ previous inflow. The number of slots in the buffer
is equal to the number of time steps that a flow gets delayed with. The number of slots is computed as floor dt/K, where K can vary among reaches, and
dt [time] is the simulation time step. The latter must be constant during a simulation; for months, a standard month length (30 days) is assumed.
Delay parameter
The K parameter specifies the time for the incremental flood wave to traverse
the river between the selected river node and the next downstream node. Its
value may also be estimated as the observed travel time of a distinct hydrograph peak between two nodes.
6.5.2
Water level Calculation
In most applications, the Basin module is used only to calculate flows, not
water levels. The Basin module is not a hydraulic model and thus cannot be
used for proper flood modelling. The River module is more suited for such
purposes. However, Water level calculations can be done in the Basin module. If the Water Quality module has been enabled water level calculations
are required.
Two methods are available for Water level calculations:

Rating curve approach (Q-h table)

Manning formula.
Both apply for steady-state flow and are thus approximations, but they are
usually reasonable estimates as long as the water level does not change rap-
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Routing
idly (e.g. during a flood). The items in the dialogue window change depending
on the option chosen.
Rating curve approach
When the Rating Curve approach is used, it looks up the water level in a user
specified Q-h table. The table must cover the range of discharges encountered during a simulation.
Manning formula
The Manning formula is:
Q = 1nAR
2  3
 S
(6.10)
Where n is the Manning’s number n, A is the cross-sectional area, S is the
water surface slope, R is the resistance radius:
B
2


2
3  2
32
R = 1  A   hb
db  =  1  A  h  B 


(6.11)
0
assuming a rectangular cross-section with width B, and h(b)=h
so R can be written as:
R= 1  h  h
32 2
 as B  A = 1  h
and
Q = 1nhBh
2  3
 S = 1nh
5  3
B S
(6.12)
Thus water level can be computed as:
h = Q  n  B  S
3  5
(6.13)
The parameters to be specified for the Manning formula are already specified
elsewhere for the River Module, but must be specified here for the Basin
Module:
Manning’s number
Here the Manning number must be specified.
Slope
Here you can enter the slope. Generally, it is a good approximation to equate
surface and channel slope.
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River Network
Max level (optional)
Optionally, you can also specify a maximum water depth up to which results
from the Manning formula are accepted. If you specify such a (non-zero)
value, water levels will never exceed it.
Width
Cross section width B, used in the water level calculations. It is assumed that
the cross-section is rectangular.
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7
Catchments
Catchments are generally included in a model to provide catchment runoff as
an inflow to the River network. A model may contain any number of catchments.
Catchments may be represented schematically, or by their delineated boundaries as illustrated in figure below. The primary difference between schematic
and delineated catchments in a model setup is, that the catchment surface
area is directly derived from the delineation of catchments whereas the surface area must be specified manually for the schematic catchments.
Figure 7.1
Illustration of catchments in a MIKE HYDRO model
Runoff from catchments are either user-defined through a predefined runoff
time series file or it can be calculated using one of several rainfall runoff models available. Runoff from a catchment is added to a river network in catchment nodes.
Additional features and calculation options related to catchments include
groundwater and definition of sediment load as input to a reservoir sedimentation calculation.
Creating a catchment
There are several ways of creating catchments, each of them being related to
a specific Add button under the Catchments ribbon in Map view.
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Catchments
Figure 7.2
Catchment ribbon in Map view
MIKE HYDRO offer multiple options for catchments definitions



Sketched Catchments are created by selecting the ‘Add sketch’ button
and clicking on the branch at the downstream end of a catchment. Here
a catchment node will be automatically inserted. The upstream end of a
catchment is given by the next upstream catchment node or the end of
the branch.
Delineated catchments may be created by using a DEM (cf. Section 5.4
(Digital Elevation Model (DEM)). This type of catchment is added by
pressing the ‘Add delineate’ button and clicking on the branch at the
downstream end of a catchment. The catchment is automatically delineated based on the elevations from the DEM, and a catchment node is
automatically inserted.
Digitized catchments may be drawn on the map using the ‘Add digitize’
button. For this type of catchment, the connection to the branch has to be
manually defined with a connection. The catchment connections can be
created and edited using the buttons from the Connection group in the
ribbon.
Note that a catchment created from the map, regardless of its type (sketched,
delineated or digitized), can have its shape corrected from a shape file using
the ‘Load shape’ button in the Tabular tab. This however does not change the
catchment connection or the catchment node.
Note that delineated catchments starting in a local depression (area with local
minimum values) can have an unexpected result as an artificial flow pattern in
the lake is used for defining the catchment boundary.
If 'Ctrl'-button is pressed when inserting the catchment outlet the catchment
will include both the entire lake and the catchment to the lake.
Editing a catchment
The ‘Edit’ button from the Catchment group in the ribbon may be used to edit
the geometry of a catchment on the map. After selecting this button and clicking on the desired catchment, all the vertices defining the polygon of the
catchment become visible.
To move a vertex, click and drag the selected vertex.
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MIKE HYDRO - © DHI
Catchment definitions
To add a new vertex, click on the desired location along the edge of the
catchment.
To delete a vertex, double click the selected vertex.
Note that to delete multiple vertices at the same time, zoom out in such a way
that these vertices appear almost superimposed. After double clicking, all the
vertices in the vicinity of the selected location will be deleted.
Deleting a catchment
To delete a catchment from the map, select the ‘Delete’ button in the Catchment group in the ribbon and click on the desired catchment.
To delete one or more catchments from the Tabular tab, highlight the catchment(s) to be deleted in the overview table and press the ‘Delete’ button
above the table.
Connecting a catchment
The three buttons from the Connection group in the ribbon are described
below:
Select. This button can be used to select one or more catchment connections. To select multiple connections, press the ‘Ctrl’ key on the keyboard
while selecting the items on the map.
Add. Select the ‘Add’ button to connect a catchment to a branch, or to connect it to a new location. After pressing the ‘Add’ button, click on the border of
a catchment and drag to the branch. A catchment node is added at the connected location on the branch. Edit. This button may be used to move the
connection to another location. To edit the connection, first click the ‘Edit’ button and click once on the connection, then drag the white symbol to its new
location. Click once again to stop editing. When a catchment is connected to
a new location on a branch, a new catchment node is added to this branch.
7.1
Catchment definitions
Depending on the selected options, the Catchment definitions dialogue may
contain the following tabs:

General

Groundwater

Rainfall-Runoff

Sediment Load
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Catchments
7.1.1
General
Under the General tab the following catchment properties are specified:

Area

Groundwater model

Rainfall-runoff model

Runoff time series

Calibration plot

Load shape
Area
When catchment runoff is specified as specific runoff rates (e.g. litres/sec/m2)
an accurate specification of the catchment area is required in order to calculate the runoff volume (area * specific runoff). When the runoff volumes are
specified as discharges (e.g. m3/s), the catchment area is not used.
Catchment areas can either be assigned manually, or calculated automatically based on the catchment shapes on the map by enabling ‘Use catchment
shape for area calculation’. By default the calculated catchment areas are
used. For sketched catchments a manual specification of the catchment area
is normally required, whereas for delineated catchments the calculated area
can normally be used. To manually assign catchment area, the option ‘Use
catchment shape for area calculation’ must be disabled.
Groundwater model
Three choices are available for the groundwater modelling of the catchment:

No groundwater model included

Single-layer groundwater model

Two-layer groundwater model
A groundwater model can only be selected if groundwater has been included
in the Basin modules. By default the menu assumes that there is no groundwater model for the catchment. In such a case groundwater can only be used
if the option ‘Unlimited groundwater in catchments without groundwater
model’ is selected/enabled.
If a groundwater model is selected, groundwater parameters must be specified under the groundwater tab.
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Catchment definitions
Rainfall-runoff model
By default a rainfall-runoff model is not selected. A rainfall-runoff model can
only be selected if the rainfall-runoff module has been included in the Modules menu.
The following types of rainfall-runoff models are offered:

NAM

UHM
Runoff time series
If a rainfall-runoff model has not been selected a runoff time series must be
specified for the catchment. Catchment runoff can be specified either as Specific runoff (volume per time per unit area) or as Discharge (volume per time).
To specify the runoff time series click on the
button and click Browse...
to select an existing time series or click Create a new file… to open the ‘Create a new file’ dialogue.
When a groundwater model has been included, total catchment runoff is calculated by adding baseflow to the user-specified runoff time series. The user
specified runoff is not routed through the groundwater aquifers, but represents the fast catchment response. In this case it is important that user-specified runoff time series only include the surface/interflow components of the
hydrograph and not the baseflow component. If baseflow is included in the
user-specified runoff time series, baseflow will be overestimated.
When a rainfall-runoff model is selected, catchment runoff is automatically
calculated and the baseflow component is only included if no groundwater
model is present in the catchment.
If the specified time series does not cover the entire simulation period, it will
automatically be recycled (cf. ‘Time Series’ in MIKE Zero).
Calibration plot
It is possible to save the calibration plot by enabling ‘Calibration plot’. The
calibration plot shows observed and simulated runoff for the catchment, cf.
Section 7.1.3.
Load shape
It is possible to import/load the shape of a catchment directly. Click ‘Load
shape’, select the relevant shape file and choose the shape item that represents the catchment.
Note: this functionality will only edit the shape of the active catchment on the
map. It will not create any new catchment. Instead, it is possible to import and
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create one or multiple catchments at once from a shape file. To achieve this,
please see section Import from Shapefile.
7.1.2
Groundwater
It is assumed that the lateral boundaries of subsurface (groundwater) and
surface catchments are the same. The groundwater storage (aquifer) is conceptualised as a linear reservoir model (cf. “The Linear Reservoir Model” on
page 185) with one or two layers. The conceptual structure of the two-layer
groundwater component is shown in Figure 7.3. A single layer model only
include the shallow (upper) aquifer.
Figure 7.3
Conceptual structure of the groundwater component
As illustrated in Figure 7.3 groundwater interacts with the surface water via
groundwater recharge, groundwater discharge and seepage from river
branches, reservoirs and connections. Moreover, when the water table of the
shallow (upper) aquifer reaches the land-surface, it starts to spill directly into
the river. Finally, groundwater from the deep aquifer can be pumped by water
users.
Note that groundwater pumping is assumed to take place from the deep aquifer unless a one-layer aquifer has been specified (then pumping takes place
from the shallow aquifer).
Under the Groundwater tab three types of groundwater properties/parameters are specified:
80

Depths

Time constants
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Catchment definitions

Groundwater recharge time series
Properties can only be specified if a groundwater model has been selected
under the general tab.
Depths
Initial water table depth
The initial water table depth (relative to ground surface) determines the magnitude of the groundwater discharge and the available water for pumping in
the initial period of simulation. Depending on the time constant specified the
initial depth may influence the results during a few days or up to several
months of the simulation.
Outlet depth
The outlet depth (relative to ground surface) determines the storage capacity
of the shallow aquifer and the storage capacity available for baseflow generation in the deep aquifer. For shallow aquifers the water table can vary
between the outlet depth and ground surface (depth = 0 metres) at which
time overflow of groundwater occurs to the river. For deep aquifers (only relevant if a two-layer groundwater model is selected) with no pumping, the water
table (used for calculating baseflow) can vary between the outlet depth of the
deep aquifer and the outlet depth of the shallow aquifer, at which time overflow of groundwater from the deep to the shallow aquifer occurs.
Bottom level (only relevant for deep aquifer)
Bottom level is the lowest level (largest depth relative to ground surface) from
which water can be pumped from the deep aquifer. This indicates the total
storage available for usage from the deep aquifer.
Time constants
A time constant (cf. ‘The Linear Reservoir model’ in the Appendix) is used to
calculate the rate at which groundwater discharges into the river (as baseflow). The larger the time constant the lower the rate of discharge. A high time
constant reflects a more constant baseflow contribution.
When a two-layer model is selected, separate time constants must be specified for the Shallow aquifer and the Deep aquifer. Additionally, a time constant
must be specified for the interface between shallow and deep aquifers. This
constant is used to calculate the rate at which water percolates from the shallow to the deep aquifer.
Groundwater recharge time series
A groundwater recharge time series must be specified if no rainfall-runoff
model is selected under the General tab.
Click on the
button and click Browse... to select an existing time series
or click Create a new file… to open the ‘Create a new file’ dialogue.
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Groundwater recharge is automatically calculated when a rainfall-runoff
model is selected.
7.1.3
Rainfall-Runoff
Rainfall-runoff modelling is a first stage of the simulation that creates the runoff time series for the individual catchments. The simulation of the flow in the
river branches is performed at a second stage.



There are several rainfall-runoff models available:
NAM. A lumped, conceptual rainfall-runoff model, simulating the overland flow, interflow, and baseflow components as a function of the moisture contents in four storages.
UHM. The Unit Hydrograph Model includes different loss models (constant, proportional) and the SCS method for estimating storm runoff.
Note: The rainfall-runoff tab is available only if the rainfall-runoff module is
activated in the Modules menu (4.1.1) and if a rainfall-runoff model has been
selected for the catchment in the General tab.
7.1.4
NAM
The NAM model is a deterministic, lumped and conceptual rainfall-runoff
model accounting for the water content in up to four different storages. NAM
can be prepared in a number of different modes depending on the requirement. As default, NAM is prepared with nine parameters representing the surface zone, root zone and the groundwater storages.
In addition, NAM contains provision for:

Extended description of the groundwater component.

Two different degree day approaches for snow melt.
The NAM Rainfall-runoff component is accessed once the NAM model is
selected under the General tab.
More details on the NAM model can be found in the ‘MIKE 1D Reference’
manual.
In the NAM model, the following sections can be found:
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
Surface-rootzone

Groundwater

Snow melt

Elevation zones
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
Irrigation

Initial conditions

Autocalibration

Seasonal variation

Time series
The parameters of each section are specified for each representative catchment.
The NAM Rainfall-runoff simulation covers the period as specified in the Simulation period dialogue (“Simulation Period” on page 52).
Surface-rootzone
Storages


Maximum water content in surface storage (Umax). It represents the
cumulative total water content of the interception storage (on vegetation),
surface depression storage and storage in the uppermost layers (a few
cm) of the soil. Typical values are between 10-20 mm.
Maximum water content in root zone storage (Lmax). It represents
the maximum soil moisture content in the root zone, which is available
for transpiration by vegetation. Typical values are between 50-300 mm.
Runoff parameters




Overland flow runoff coefficient (CQOF). It determines the division of
excess rainfall between overland flow and infiltration. Values range
between 0.0 and 1.0
Time constant for routing interflow (CKIF). It determines the amount
of interflow, which decreases with larger time constants. Values in the
range of 500-1000 hours are common.
Time constants for routing overland flow (CK1, CK2). They determine the shape of hydrograph peaks. The routing takes place through
two linear reservoirs (serially connected) with different time constants,
expressed in [hours]. High, sharp peaks are simulated with small time
constants, whereas low peaks, at a later time, are simulated with large
values of these parameters. Values in the range of 3-48 hours are common.
Root zone threshold value for overland flow (TOF). It determines the
relative value of the moisture content in the root zone (L/Lmax) above
which overland flow is generated. The main impact of TOF is seen at the
beginning of a wet season, where an increase of the parameter value will
delay the start of runoff as overland flow. Threshold value range between
0 and 70% of Lmax, and the maximum value allowed is 0.99.
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
Root zone threshold value for interflow (TIF). It determines the relative value of the moisture content in the root zone (L/Lmax) above which
interflow is generated.
Groundwater
For most NAM applications only the Time constant for routing baseflow
(CKBF) and possibly the Root zone threshold value for groundwater recharge
(TG) need to be specified and calibrated. However, to cover also a range of
special cases, such as groundwater storages influenced by river level variations, a number of additional parameters can be modified.
The groundwater parameters are:





84
Root zone threshold value for GW recharge (TG). It determines the
relative value of the moisture content in the root zone (L/Lmax) above
which groundwater (GW) recharge is generated. The main impact of
increasing TG is less recharge to the groundwater storage. Threshold
values range between 0 and 70% of Lmax and the maximum value
allowed is 0.99.
Time constant for routing baseflow (CKBF). It can be determined from
the hydrograph recession in dry periods. In rare cases, the shape of the
measured recession changes to a slower recession after some time. To
simulate this, a second groundwater reservoir may be included, see the
extended components below.
Ratio of GW-area to catchment area (Carea). This parameter
describes the ratio of the groundwater catchment area to the topographical surface water catchment area, which is specified under the General
tab. Local geological condition may cause part of the infiltrating water to
drain to another catchment. This loss of water is described by a Carea
less than one. Usual value: 1.0.
Specific yield of groundwater reservoir (Sy). This parameter should
be kept at the default value except for the special cases in which the
groundwater level is used for NAM calibration. This may be required in
riparian areas, for example, where the outflow of groundwater strongly
influences the seasonal variation of the levels in the surrounding rivers.
Simulation of groundwater level variation requires values of the specific
yield Sy and of the groundwater outflow level GWLBFO, which may vary
in time. The value of Sy depends on the soil type and may often be
assessed from hydro-geological data, e.g. test pumping. Typically values
of 0.01-0.10 for clay and 0.10-0.30 for sand are used.
Maximum GW-depth causing baseflow (GWLBF0). It represents the
distance in meters between the average catchment surface level and the
minimum water level in the river. This parameter should be kept at the
default value except for the special cases in which the groundwater level
is used for NAM calibration, cf. Sy above.
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



Seasonal variation of GW-depth causing baseflow. In low-lying catchments the annual variation of the maximum groundwater depth may be
of importance. This variation relative to the difference between the maximum and minimum groundwater depth can be entered if the checkbox is
ticked. The monthly values are given relative to the difference between
GWLBF0 and GWLBF_min [0-1]. This is done in the Seasonal variation
page, in the column Variation of groundwater maximum water depth.
Minimum GW-depth for seasonal variation (GWLBF_min). If the Seasonal variation of GW-depth causing baseflow is selected, the minimum
GW-depth level [m] has also to be entered for the calculations.
Capillary flux, depth for unit flux (GWLBF1). It is defined as the depth
of the groundwater table generating an upward capillary flux of 1 mm/day
when the upper soil layers are dry corresponding to wilting point. The
effect of capillary flux is negligible for most NAM applications. Keep the
default value of 0.0 to disregard capillary flux.
Use abstraction. If this option is selected, it is possible to specify the
groundwater abstraction depth from the catchment.
The input type of this variable can be:
–
–


Time series. If this option is selected, a time series of abstraction
depth has to be entered in the Time series page.
Seasonal variation. This option allows to specify monthly values of
abstraction depth in the Seasonal variation page.
Use lower baseflow, recharge to groundwater (Cqlow). The groundwater recession is sometimes best described using two linear reservoirs,
with the lower usually having a larger time constant. In such cases, the
recharge to the lower groundwater is specified here as a percentage of
the total recharge.
Time constant for routing lower baseflow (Cklow). It is specified for
Cqlow > 0 as a baseflow time constant, which is usually larger than the
CKBF.
Snow melt
The snow module simulates the accumulation and melting of snow in a NAM
catchment. It is included in the model when the ‘Include snow melt’ checkbox
is ticked.
Two degree day approaches can be applied: a simple lumped calculation or a
more advanced distributed approach. The simple degree-day approach uses
only two overall parameters: a Constant Degree day coefficient and a Base
temperature (snow/rain). The distributed approach allows the user to specify
a number of elevation zones within a catchment with separate snow melt
parameters, temperature and precipitation input for each zone.
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The snow melt module uses a temperature input time series, usually mean
daily temperature. This has to be specified in the Time series tab.
The snow melt parameters are:


Constant Degree day coefficient (Csnow). The content of the snow
storage melts at a rate defined by the degree-day coefficient multiplied
by the temperature difference above the Base temperature. Typical values for Csnow are 2-4 mm/day/C.
Base temperature (snow/rain) (To). The precipitation is retained in the
snow storage only if the temperature is below the base temperature,
whereas it is by-passed to the surface storage (U) in situations with
higher temperatures. The base temperature is usually at or near zero
degree C.
It is also possible to specify other input parameters for the snow melt module,
if the relative checkboxes are ticked. These are:

Variation of degree day coefficient. This option is selected when the
melting coefficient is varying in time, instead of being constant. The input
for this model can be specified in two ways:
–
–


Specify as time series file. In this case the melting coefficient is
specified in a time series that has to be loaded in the Time series
section.
Specify as seasonal variation. If this option is selected, monthly
values of the degree day coefficient for snow melt must be specified
in the Seasonal variation section.
Radiation coefficient (Radiation file on time series page). This option
may be introduced when time series data for incoming radiation is available. The time series input file is specified separately on the Time series
section. The total snow melt is calculated as a contribution from the traditional snow melt approach based on Csnow (representing the convective
term) plus a term based on the radiation.
Rainfall degree day coefficient. This option may be introduced when
the melting effect from the advective heat transferred to the snow pack
by rainfall is significant. This effect is represented in the snow module as
a linear function of the precipitation multiplied by the rainfall degree coefficient and the temperature deviation above the base temperature.
Elevation zones
The Elevation zones tab becomes available when snow melt is included in
the model. When the ‘Delineate catchment into elevation zones for snow
modelling’ option is selected, the snow melt distributed approach is applied.
Following this approach, the catchment is divided into a certain number of
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elevation zones, each with specific snow melt parameters, temperature and
precipitation inputs.
The general parameters that have to be specified for the snow melt model
are:






Number of elevation zones
Reference level for temperature station. This parameter defines the
altitude [m] of the reference temperature station. This station is used as a
reference for calculating the temperature and precipitation within each
elevation zone (the file with temperature data is specified on the Time
series page).
Dry temperature lapse rate. It specifies the vertical gradient [C/100 m]
for adjustment of temperature under dry conditions. The temperature in
the actual elevation zone is calculated based on a linear transformation
of the temperature from the reference station to the actual zone, the correction being defined as the dry temperature lapse rate multiplied by the
difference in elevations between the reference station and the actual
zone.
Wet temperature lapse rate. This parameter specifies the vertical gradient [C/100 m] for adjustment of temperature under wet conditions
defined as days with precipitation higher than 10 [mm]. The temperature
in the actual elevation zone is calculated based on a linear transformation of the temperature from the reference station to the actual zone, the
correction being defined as the wet temperature lapse rate multiplied by
the difference in elevations between the reference station and the actual
zone.
Reference level for precipitation station. This parameter defines the
altitude, expressed in [m], at the reference precipitation station (the file
with precipitation data is specified on the Time series page).
Correction of precipitation rate. This parameter specifies the vertical
gradient for adjustment of precipitation and is expressed in [percent/100
m]. The precipitation in the actual elevation zone is calculated based on
a linear transformation of the precipitation from the reference station to
the actual zone, the correction being defined as correction of precipitation rate [percent/100 m] multiplied by the difference in elevation
between the reference station and the actual zone.
The specific parameters for each elevation zone are entered in the table at
the bottom of the page. These are:

Zone. Zone number ID automatically assigned by the programme.
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







Elevation. The elevation of each zone is specified in the table as the
average elevation of the zone. The elevation must increase from zone (i)
to zone (i+1).
Area. The area of each zone is specified in the table. The total area of
the elevation zones must equal the area of the catchment.
Min storage for full coverage. This parameter defines the required
amount of snow to ensure that the zone area is fully covered with snow.
When the water equivalent of the snow pack falls under this value, the
area coverage (and the snow melt) will be reduced linearly with the snow
storage in the zone.
Max storage in zone. This value defines the upper limit for snow storage in a zone. Snow above this value will be automatically redistributed
to the neighbouring lower zone.
Max water retained in snow. It defines the maximum water content in
the snow pack of the zone. Generated snow melt is retained in the snow
storage as liquid water until the total amount of liquid water exceeds this
water retention capacity. When the air temperature is below the base
temperature To, the liquid water of the snow re-freezes with rate Csnow.
Dry temperature correction. The actual temperature correction for dry
conditions to estimate actual temperature for the specific zone.
Wet temperature correction. The actual temperature correction for wet
conditions to estimate actual temperature for the specific zone.
Precipitation correction. The relative correction for precipitation,
expressed in percent, to estimate the precipitation for the specific zone.
The ‘Calculate’ button above the table fills the three columns in the table for
Dry temperature correction, Wet temperature correction and Precipitation
correction, based on the specified rates above.
Irrigation
An irrigation module is included in the rainfall-runoff model when the ‘Include
irrigation’ box is ticked. This irrigation module has a different function than the
one defined for the irrigation water user. While the latter is used to calculate
water balances at the catchment scale, the irrigation module in the rainfallrunoff model is only used for adjusting the water balance in the NAM model.
The purpose of the NAM irrigation module is that of simulating the runoff and
groundwater recharge/baseflow from the irrigated areas, so that NAM can be
calibrated for the non-irrigated part of the catchment.
Minor irrigation schemes within a catchment will normally have negligible
influence on the catchment hydrology, unless transfer of water over catchment boundaries is involved. Large schemes, however, may significantly
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affect the runoff and the groundwater recharge through local increases in
evapotranspiration and infiltration as well as through operational and field
losses.
The irrigation module of NAM may be applied to describe the effect of irrigation on the following aspects:



The overall water balance of the catchment. This will be affected
mainly by the increased evapotranspiration and by possible external
water sources for irrigation.
Local infiltration and groundwater recharge in irrigated areas.
The distribution of catchment runoff amongst different runoff components (overland flow, interflow, baseflow). This may be influenced
by the increased infiltration in irrigated areas as well as by local abstraction of irrigation water from groundwater or streams.
The irrigation parameter is:

Infiltration rate at field capacity (K0-inf). This parameter defines the
rate of infiltration at field capacity [mm/h].
The Irrigation sources in percent are:



Local groundwater (PC_LGW). Percentage of water for irrigation supplied by groundwater sources.
Local river (PC_LR). Percentage of water used for irrigation supplied by
a local river.
External river (PC_EXR). Percentage of water for irrigation supplied by
a river external from the catchment defined in NAM.
Another irrigation option is:

Include crop coefficients and operational losses. If this checkbox is
ticked, additional irrigation module parameters can be specified as
monthly values in the Seasonal variation page.
These are:
–
Irrigation crop coefficient. This parameter, also defined as Kc,
allows to quantify the amount of water required (and transpired) by
the crop. Different crops have different crop coefficient. Kc is multiplied by the reference ET of a standard crop (grass) to calculate the
water demand of the crop of interest.
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Catchments
–
Irrigation operational and conveyance losses in percent of
abstract water. These represent the system losses of irrigation
water for the different components/processes:
Groundwater
Overland flow
Evaporation
Initial conditions
The initial relative water contents of surface and root zone storage must be
specified as well as the initial values of overland flow and interflow. Initial values for baseflow must always be specified. When lower baseflow is included,
a value for the initial lower baseflow must also be specified.
Initials values of the snow storage are specified when the snow melt routine
is used. When the catchments are delineated into elevation zones, the snow
storage and the water content in each elevation zone are specified.
The parameters of the different subsections are:
Surface and rootzone




Relative water content in surface storage [0, 1] (U/UMax). This value
ranges between zero and one, where one indicates wet initial conditions
and zero dry initial conditions.
Relative water content in root zone storage [0, 1] (L/LMax). This
value ranges between zero and one.
Overland flow (QOF). The overland flow at the beginning of the simulation, which is normally estimated from the hydrograph [m3 s-1].
Interflow (QIF). The interflow at the beginning of the simulation, which is
normally based estimated from the hydrograph [m3 s-1].
Groundwater


Baseflow (BF). The baseflow at the beginning of the simulation, which is
normally estimated from the hydrograph [m3 s-1].
Lower baseflow (BF - low). The lower baseflow at the beginning of the
simulation, which is normally estimated from the hydrograph
[m3 s-1].
Snow storage
If the Elevation zones option is not selected:

Global value. This parameter represents the actual initial snow storage
in [mm] over the entire catchment.
If the Elevation zones option is selected:
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
Zone, Snow storage, and Water in snow. If the snow model is defined
using elevation zones, it is required to enter for each zone the initial
Snow storage in [mm] and the Water in snow, also in [mm], defining the
water content in the snow pack.
Autocalibration
It is possible to use an automatic optimisation procedure to calibrate the 12
most important parameters in the NAM model. The calibration routine used in
NAM is based on a multi-objective optimisation strategy, the SCE algorithm.
The procedure implemented in NAM allows to simultaneously optimise four
different calibration objectives or a combination of them. A description of the
SCE algorithm is given in the ‘Autocal User Guide’.
To include the Autocalibration routine in NAM, tick the ‘Include autocalibration’ checkbox.
Calibration parameters
The parameters which can be included in the autocalibration routine are listed
in the Calibration parameters table:

Maximum water content in surface storage (Umax).

Maximum water content in root zone storage (Lmax)

Overland flow runoff coefficient (CQOF)

Time constant for interflow (CKIF)

Time constant 1 for routing overland flow (CK1)

Time constant 2 for routing overland flow (CK2)

Root zone threshold value for overland flow (TOF)

Root zone threshold value for interflow (TIF)

Root zone threshold value for groundwater recharge (TG)

Time constant for routing baseflow (CKBF)

Lower baseflow, recharge to lower reservoir (Cqlow)

Time constant for routing lower baseflow (Cklow).
If the ‘Fit’ checkbox is ticked, the parameter is included in the autocalibration.
The table also contains the following columns:


Initial value. It is the value for the parameter specified in the Surfacerootzone or Groundwater page and used in the first model simulation.
Lower Bound and Upper Bound are the minimum and maximum values that the parameter can assume and therefore define its range of variation.
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Objective functions
In automatic calibration, the calibration objectives have to be formulated as
numerical goodness-of-fit measures that are optimised.
Four calibration objectives are defined as numerical performance measures
in the Autocalibration routine of NAM. These are selected and used by ticking
the relative checkboxes.
The objective functions are:




Overall water balance. This defines the agreement between the average simulated and observed catchment runoff overall volume error.
Overall root mean squared error. This measure defines the overall
agreement of the shape of the simulated hydrograph with the observed
one.
Peak flow RMSE. This optimisation measure defines the agreement of
simulated and observed peak flows events. If this measure is selected,
the minimum river discharge value above which the flow is defined as
peak flow has to be specified in the Peak flow field.
Low flow RMSE. This optimisation measure defines the agreement of
simulated and observed low flows events. If this measure is selected, the
maximum river discharge value below which the flow is defined as low
flow has to be specified in the Low flow field.
Other input parameters are:


Maximum number of evaluations. Here one of the stopping criteria of
the auto calibration routine is specified. The automatic calibration will
stop either when the optimisation algorithm ceases to give an improvement in the calibration objective or when the maximum number of model
evaluations is reached.
Initial number of day excluded. This is a warm up period that will be
disregarded when calculating the objecting function.
Running the autocalibration
After having entered the autocalibration parameters, the autocalibration procedure starts when launching a normal simulation. When the optimisation
routine is completed, the list of the parameters generated during the optimisation and the relative objective functions are made available in the CatchmentName-Autocal.txt file. If the Calibration plot option has been selected in the
General tab, a CatchmentName.plc file is also produced. This file shows the
differences between the observed and the best simulated runoff data, and
can be opened in the Plot Composer.
Note: The various NAM parameters shown in the Rainfall-runoff tab will not
be automatically updated with the optimal parameter set. To visualize the
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optimized parameters, either close (without saving) the MIKE HYDRO file
and re-open it, or check the created text file CatchmentName-Autocal.txt.
Seasonal variation
In this section it is possible to enter the values of some selected time varying
parameters. Monthly values have to be assigned to the parameters. Whether
a parameter has a constant or a seasonal varying value is determined in the
different sections of the NAM model.
It is possible to specify a seasonal variation for the parameters:





Variation of groundwater maximum water depth. Seasonal variation
of GW-depth causing baseflow. From Groundwater tab.
Abstraction. Groundwater abstraction depth. From Groundwater tab.
Degree day coefficient for snow melt. Melting coefficient for snow
melt. From Snow melt tab.
Irrigation crop coefficient. Parameter to quantify the amount of water
required (and transpired) by the crop. From Irrigation tab.
Irrigation operational and conveyance losses in percent of
abstracted water. System losses of irrigation water for the different components/processes: Groundwater, Overland flow and Evaporation.
From Irrigation tab.
Time series
In this section the input time series of the rainfall-runoff model are entered.
Depending on which module of the model is used, these are:



Rainfall. Always to be entered. A time series, representing the average
catchment rainfall. The time interval between values may vary through
the input series. The rainfall specified at a given time should be the rainfall volume accumulated since the previous value.
Evaporation. Always to be entered. The potential evaporation is typically given as monthly values. Like rainfall, the time for each potential
evaporation value should be the accumulated volume at the end of the
period it represents. The monthly potential evaporation in June should be
dated 30 June or 1 July.
Observed discharge. This time series has to be entered if the Autocalibration module is used or the ‘Calibration plot’ option has been selected
in the General tab. The inclusion of the observed discharge will automatically enable additional outputs which include a calibration plot with comparison of observed and simulated discharge and calculation of
statistical values.
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




Temperature. A time series of temperature, usually mean daily values, is
required only if snow melt calculations are included in the simulations.
Irrigation. To be entered when the irrigation module of the rainfall-runoff
module is included.
Abstraction depth. To be entered when the ‘Use abstraction’ option in
the Groundwater tab is selected and ‘Time series file’ is specified.
Radiation. To be entered when the ‘Radiation coefficient’ option in the
Snow melt tab is selected.
Degree day coefficient. To be entered when the ‘Variation of degree
day coefficient’ option in the Snow melt tab is selected.
Weighted time series may be used for some time series by enabling ‘Use
weighted time series’. This adds a new tab ‘TS weighted rainfall/evaporation/temperature’ to the window (see below).
Weighted time series
To use weighted time series, ‘Use weighted time series’ must be enabled
under the Time series tab - see above. Under the TS weighted tab the following may be defined:
Allow gap in time series
If ‘Allow gap in time series’ is enabled, simulation will proceed despite missing data (gap) in the time series. If ‘Allow gap in time series’ is disabled, simulation will terminate with an error message if missing data (gaps) are
encountered in the time series.
Distribution in time
If data is available from stations reporting at different frequencies, e.g. both
daily and hourly stations, the Distribution in time of the average catchment
rainfall may be determined using a weighted average of the high-frequency
stations. You may, for example, use all daily and hourly stations to determine
the daily mean rainfall over the catchment and subsequently use the hourly
stations to distribute (desegregate) this daily rainfall in time.
Weighted average combinations
To specify a weighted average combination, add time series by clicking the
Append ‘+’ button above the table to add a new row, then click the browse ‘...’
button to select a time series or create a new file and enter the weight to be
assigned to that time series. Repeat the steps for all relevant time series/stations.
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Catchment definitions
The weighted average values Tweighted are computed using the following formula:
T0  w0 + T1  w1 +  + Tn  wn
T weighted = ---------------------------------------------------------------------------w0 + w1  w1 +  + wn
(7.1)
where Tn is the value from time series n and wn the corresponding weight.
If data are missing from one or more time series/stations, and ‘Allow gap in
time series’ is enabled, the Mean Area Weighting algorithm will ignore the
time series with missing data.
In the present version it is possible to specify only one weighted average
combination.
7.1.5
UHM
The UHM (Unit Hydrograph) model constitutes an alternative to the NAM
model for flood simulation in areas where no streamflow records are available
or where unit hydrograph techniques are already well established.
The model includes a number of simple unit hydrograph models to estimate
the runoff from single storm events by the use of the well-known unit hydrograph technique. The models divide the storm rainfall in excess rainfall (or
runoff) and water loss (or infiltration).
More details on the UHM model can be found in the ‘MIKE 1D Reference’
manual.
UHM parameters
The following parameters are used for all types of UHM models:

Adjustment and baseflow

Hydrograph

Enlargement and loss model

Lag time
Adjustment and baseflow


Area adjustment factor. This adjustment factor (different from 1.0) may
be applied if the catchment rainfall intensity is assumed to differ from the
input rainfall data series by a proportional factor.
Baseflow. If different than zero, the value specified represents a constant baseflow that is added to the runoff.
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Catchments
Hydrograph
The distribution of the runoff in time can be described using different methods.
Three different options can be selected for the hydrograph type:



SCS triangular. This is a standard hydrograph in which the time to peak
is assumed to be half the duration of the excess rainfall plus the lag time
tl.
SCS dimensionless. This type of hydrograph has been derived from a
large number of natural unit hydrographs from catchments of varying
size and location. The flow values are expressed in Q/Qp, where Qp is
the peak discharge, and the time in T/Tp, where Tp is the time from the
start of the hydrograph rise to the peak.
User defined. This hydrograph should be specified in its dimensionless
form, i.e. Q/Qp as a function of T/Tp, as for the SCS dimensionless
hydrograph above. But in this case this information has to be provided in
the Hydrograph table (Dimensionless from Q/Qp as a function of
T/Tp). The hydrograph table must be provided in a time series file,
where the axis type is either ‘Equidistant Relative Axis’ or ‘NonEquidistant Relative Axis’ and containing one item with the type
‘Dimensionless factor’.
Enlargement and loss model
Four different options are available to represent the loss model, each of them
requiring different inputs.
These types of loss models are:




Constant loss. In this case the infiltration is described as an Initial Loss
at the beginning of the storm followed by a Constant Loss term caused
by infiltration.
Proportional loss. If this model is selected, a Runoff coefficient should
be specified as the ratio of runoff to the rainfall.
SCS method. The SCS Loss Model uses a Curve number that characterises the catchment in terms of soil type and land use characteristics.
The model also requires an Initial AMC (antecedent moisture conditions)
parameter.
SCS generalised. The SCS generalised loss model does not make use
of the concept of an antecedent moisture content (AMC) but applies a
storage Initial abstraction depth. Like in the SCS method, the Curve
number should be specified for the SCS generalised.
Lag time
The Lag time type for the UHM model can be specified in two different ways:
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Catchment definitions
User specified. In this case the lag time is specified directly in hours.

Curve number method. In this case the lag time is calculated by the
standard SCS formula and will appear in the Derived Lag Time box.
When this method is selected, three parameters need to be specified:
Hydraulic length, the Slope of the catchment and the Curve number.

Time series
In this section the input time series of the rainfall-runoff model are entered.
The UHM only requires two input time series:


Rainfall. This time series represents the average catchment rainfall. The
time interval between values, may vary through the input series. The
rainfall specified at a given time should be the rainfall volume accumulated since the previous value.
Evaporation. The potential evaporation is typically given as monthly values. Like rainfall, the time for each potential evaporation value should be
the accumulated volume at the end of the period it represents. The
monthly potential evaporation in June should be dated 30 June or 1 July.
Weighted time series may be used by enabling ‘Use weighted time series’.
This adds a new tab ‘TS weighted rainfall/evaporation’ where time series,
their corresponding weights and distribution in time may be defined (see
‘Weighted time series’ previous to this section).
Table 7.1
Default hydrological parameters for Kinematic wave surface runoff
model
Default values for hydrological parameters
Impervious
Parameter
Pervious
Steep
Flat
Small
Medium
Large
Area fraction (-)
0
0.4
0
0
0.6
Wetting (m)
5.00E-5
5.00E-5
5.00E-5
5.00E-5
5.00E-5
Storage (m)
-
6.00E-4
1.00E-3
1.00E-3
2.00E-3
Start inf. rate (m/s)
-
-
8.00E-7
8.00E-7
2.00E-5
End inf. rate (m/s)
-
-
8.00E-7
8.00E-7
3.00E-6
Wet exponent (s-1)
-
-
0
0
1.50E-3
Dry exponent (s-1)
-
-
0
0
3.00E-5
Manning (m1/3s-1)
80
70
30
30
12
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7.1.6
Sediment Load
Important: The Sediment load tab is only available if ‘Include reservoir sedimentation’ is selected in the Basin modules (See “Include reservoir sedimentation” on page 50.).
Under the Sediment load tab the total load and the grain size class distribution of sediment supplied by the catchment is specified. This allows the calculation of load for each sediment grain size class.
To add a total sediment load time series, click the
button and click
Browse... to select an existing time series or click on Create a new file… to
open the ‘Create a new file’ dialogue.
To specify the sediment grain size class distribution add a fraction time series
to each grain size class. This is done by selecting a sediment grain
size class and clicking on the
button and clicking Browse... to select
an existing time series or clicking Create a new file… to open the ‘Create a
new file’ dialogue. The fraction time series can be given as percentage or as
fraction. The sum of fractions must equal one at each time step.
Note: The sediment grain size classes must be globally defined by their settling velocities under 12.1 Sediment Properties (p. 160).
7.2
Combined Catchments
A combined catchment is a catchment made up with a number of sub-catchments, which are defined in the Catchment definitions menu.
The runoff from the combined catchment is found by simple addition of the
simulated runoff from each of the subcatchments. This type of catchment can
especially be used during the calibration process to quickly get the total runoff
at a gauge location, based on all upstream sub-catchments.
Combined catchments are not shown on the map, and can only be edited
from the Tabular tab. Use the Append ‘+’ or Delete ‘-’ buttons above the overview table to add or remove a combined catchment.
The various properties specified for a combined catchment are described
below.


98
Combined catchment name. The combined catchment can be given
any name.
Total area. The total area of the catchment is automatically computed,
and is equal to the sum of the areas from all its subcatchments.
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Hotstart files



7.3
Subcatchments. All subcatchments have to be added in this table using
the Append ‘+’ button. They can be deleted using the Delete ‘-’ button.
Each subcatchment has to be selected from the drop-down list amongst
the catchments defined in the Catchment definitions menu. The area
considered for each subcatchment is always its total area.
Calibration plot. It is possible to save the calibration plot by enabling
‘Calibration plot’. The calibration plot shows observed and simulated runoff for the catchment.
Observed discharge. When the ‘Calibration plot’ is enabled, a time
series of observed runoff has to be specified here with the Browse '…'
button.
Hotstart files
The initial conditions for a NAM simulation may be loaded from an existing
rainfall-runoff result file by enabling ‘Use hotstart files’ and clicking on the
‘Append’ button. This will add a new row to the list of Hotstart files. Click on
the ‘Browse’ button and select the required hotstart file.
Important: Initial conditions are read in the additional result files having the
extension _AddNAM.res1d. Therefore, only this type of file can be selected
here. The file has to be created using the ‘Create runoff hotstart files’ in the
Standard results menu.
Note: It is possible to define multiple hotstart files covering different or overlapping areas. If some catchments are covered by more than one hotstart file
the first hotstart file will be used. The ‘Move up’ and ‘Move down’ arrows may
be used to modify the order of the hotstart files. If a catchment is not covered
by any of the specified hotstart files, the initial conditions are those specified
in the Catchment definitions menu.
Use simulation start time
If ‘Use simulation start time’ is enabled, the initial condition will automatically
be extracted from the Hotstart file using the simulation start date and time as
specified in the Simulation period page.
Date and Time
The date and time at which the initial conditions are loaded from the hotstart
file. If ‘Use simulation start time’ is enabled the hotstart date and time will be
taken as the simulation start.
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8
Water Users
Water users represent water consuming activities withdrawing water from the
river or a reservoir.
A model setup may contain any number of Water users where MIKE HYDRO
overall supports two types of water users; Irrigation water users and Regular
water user (e.g. municipal, industrial and any other type of Water user).
Water users a connected to the river network through Supply flow connections and Return flow connections, where supply flow is being extracted from
the supply connection point and the Return flow is the water returned from
the water user once the final consumption has been calculated. Water user
definitions and options for connections are illustrated in the figure below.
Figure 8.1
Illustration of Water users connected to the River network through Supply connections and Return flow connections
Two different entries are available for defining Water Users:


Water User definitions (General parameters, Supply and Return flow
connection details)
Irrigation data definitions (Irrigation method applied, Crop definition as
well as Soil and Runoff model specifications)
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Water Users
Inserting a water user
To insert a Water user (regular and irrigation) in the model select the ‘Add’
button under the Water user ribbon in Map view and click on the desired location of the Water user in the map.
Figure 8.2
Insert a Water user
Note that the location is for visual purposes only and has no impact on the
model setup.
A Water user can extract water from one or several Branches and/or Reservoirs, as well as from groundwater storage. A Water User can return unconsumed water to one or more Branches (return flow).
Use the ‘Add Connection’ button under the Water user ribbon in Map view to
connect a Water user to its water extraction points (Supply connections) and
to downstream return flow points (Return flow connections) on Branches or
Reservoirs. The digitisation of a Connection must always be done in the
direction of the flow, i.e. from extraction point to Water user, or from Water
user to return flow point. Single-click on the starting point of the Connection
and drag the Connection to the desired end point.
Note that the cursor changes to a cross when properly placed. To complete
the Connection release the mouse button.
A River node is automatically inserted on the extraction point/return flow
point.
Note that the flow direction of the connection is shown with an arrow in the
Map view.
Specifying water user properties
The Water user properties dialogueue contains the following tabs:
102

General

Supply Connections

Return Flow Connections
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General

Irrigation Scheme (for irrigation users only)

Irrigated Field (for irrigation users only)
Use the table in the lower part of the properties dialogue to navigate to a particular Water user.
8.1
General
Under the General tab three types of information can be specified.
8.1.1
1.
Type of water user
2.
Water demand time series and demand carry-over fraction
3.
Groundwater properties
Type of water user
Specify the type of Water user: regular or irrigation.
Important notice for Irrigation users:
If irrigation users have a significant surface area compared to the area of the
Catchment, in which they are located, it is important to subtract the irrigated
area from the Catchment area. This is done by enabling the option; ‘Subtract
area of irrigation users and reservoirs from catchment area to calculate runoff’ in the ‘Simulation specifications -> Modules’ page of MIKE HYDRO.
Note that an irrigation Water user with a user specified water demand series
(e.g. not using the irrigation module to calculate water demand) must be
treated as a regular Water user.
8.1.2
Water demand time series and demand carry-over fraction
For a regular Water user, a water demand time series must be specified.
This is done by clicking on the
button and clicking Browse... to select
an existing time series file or by clicking Create a new file… to open the ‘Create a new file’ dialogue.
The Water demand time series dialogue contains two items:

Water demand: The total amount of water that is required to be
extracted to fulfil the water demand of the Water user.
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Water Users

Demand carry-over fraction (from one time step to next). Normally the
allocation solution is only with respect to demands in the current time
step. For some water use schemes it may be appropriate to allow deficits
to carry over from one time step to the next, resulting in a larger demand
in that next time step (larger than the “original” demand given in the
demand time series). The ‘Demand carry-over fraction’ is used to specify
the fraction of any deficit that should carry over to the following time step.
Mathematically, this is described by:
D  t + 1  = D  t + 1  + f  t   X  t 
Where D'(t+1) is effective water demand at time t+1, D(t+1) is water
demand as given in the input time series for time t+1, X(t) is calculated
deficit, and f(t) is the carry-over fraction. The latter two are calculated
at the previous time step t. The D', D, and X have units of volume,
while f is dimensionless.
If f = 0 the Deficit carry-over fraction option is ignored.
Note: Results from monthly simulations may appear to 'oscillate'. This
is not an error, but rather because the deficits in the above formula are
absolute volumes, whereas demands in the input time series must be
given as flows (volume per time). Due to the variable lengths of the
months, a constant deficit in terms of flow means a varying deficit in
terms of volume.
8.1.3
Groundwater properties
If groundwater is included in the Basin modules (cf. Section 4.1.1), three
groundwater properties must be specified: groundwater extraction method
(Groundwater options), the catchment from which groundwater is extracted
(Supply catchment), and the groundwater use time series.
Groundwater options
There are three different options for using groundwater to fulfil the Water user
demand:

104
Fraction of total demand. This method will attempt to fulfil the Water
user demand by taking a fraction of the demand from the groundwater.
This option corresponds to a specified sharing of the surface water and
the groundwater resources. If there is limited water available either in the
surface water or the groundwater the demand will not be fulfilled.
MIKE HYDRO - © DHI
General


Fraction of remaining demand. This method will attempt to use
groundwater to fulfil a fraction of the total Water user demand that cannot
be fulfilled by surface water. If the fraction is set to 1.0 it means that the
Water user first extracts surface water and then fulfils the remaining
demand using groundwater. This option corresponds to specified priority
between surface water (first priority) and groundwater.
Absolute demand. This method will subtract absolute groundwater
demand from the total water user demand to calculate surface water
demand. If absolute groundwater demand is greater than total water user
demand, surface water demand will be zero. If there is limited water
available either in surface water or in groundwater, the water user
demand will not be fulfilled.
Supply catchment
In this field you can specify the Catchment from which the groundwater is
supplied. Only valid Catchments for which groundwater aquifers exist will be
displayed in the drop down menu.
Groundwater use time series
Depending on the groundwater option selected, either a groundwater fraction
use time series or a groundwater absolute use time series must be specified.
This is done by clicking on the
button and clicking Browse... to select
an existing time series file or clicking Create a new file… to open the ‘Create
a new file’ dialogue.
Note that the groundwater use time series may optionally include two additional items: Lower groundwater extraction limit and Upper groundwater
extraction limit, where the upper groundwater depth limit specifies the depth
at which groundwater extraction may start to be reduced, and the lower
groundwater depth limit specifies the groundwater depth at which no more
extraction is allowed.
If the groundwater depth (at the beginning of the time step) is smaller than the
upper limit, there is no reduction of the extraction (a reduction factor equal to
1 is applied).
If the groundwater depth is between the upper and the lower limit, a linear
interpolation is performed on the reduction factor.
Complete reduction (reduction fraction equal to 0) takes place when the
groundwater depth is larger than the lower limit. If only one of the two time
series is given, the change in reduction factor goes abruptly from 1 to 0, when
the groundwater depth crosses this limit.
Note: The Upper groundwater depth limit should be given a value, which is
smaller than the lower groundwater depth limit.
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Water Users
8.2
Supply Connections
Under the Supply connections tab three types of attribute data can be specified:
8.2.1

Priority of supply connections

Flow loss time series

Flow capacity time series
Priority of supply connections
Here, the priority of supply connections and the supply rules are specified.
By default, supply connections are given a priority according to the sequence
in which they are digitised. The priority can be changed in the priority column.
Number 1 has first priority; number 2 has second priority, and so forth.
Two types of supply rules are available:


Call by priority: Water is supplied to satisfy the demand in the order of
priority beginning with the supply connection with the lowest ‘priority
number’.
Fraction of demand: Water supply is based on the fraction of the
demand required from each supply connection. If a supply connection
cannot fulfil its fraction there is no attempt to extract water from another
supply connection.
A fraction file, containing the fraction of demand requested from each
supply connection must be specified.
This is done by clicking on the
button and clicking Browse... to
select an existing fraction file or clicking Create a new file… to open
the ‘Create a new file’ dialogue.
Note: The sum of fractions must not exceed 1. It is possible, however,
to have a sum less than 1, with the remainder showing in the results as
“Water Demand Deficit”. Be careful, however, as it can be hard to distinguish this deficit from a “true” deficit due to lack of water.
It is possible to use a combination of Call by priority and Fraction of demand
by assigning the same priority to one or more groups of supply connections
and then specifying the fraction of demand required from each supply connection within the ‘shared priority’ group. The fractions for all supply connections within a ‘shared priority’ group must add up to one at all times.
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Supply Connections
8.2.2
Flow loss time series
Supply connections may lose water due to seepage and /or evaporation. If
these processes are considered to be of importance they may be included in
the model as a time series that specifies the losses. Both seepage and evaporation can be specified as a fraction of the actual flow (dimensionless), or as
flux (volume per time).
To add a flow loss time series, enable ‘has flow loss’, click on the
button and click Browse... to select an existing flow loss time series or click Create a new file… to open the ‘Create a new file’ dialogue.
The user-specified water demand D of the connected user is automatically
adjusted to take the loss into account. The adjusted water demand D* is calculated as follows:
D
D* = ------------------------------------- 1 – loss factor 
(8.1)
This means that the Water user demands will still be fulfilled, if sufficient
water is available at the supply source. This also applies, if the flow loss is
given as a flux.
If groundwater is defined in the Catchment where the supply connection
begins (where the extraction point is located), seepage loss is added to this
groundwater storage. However, with the current implementation seepage flow
is lost, if the supply connection begins in a catchment node.
8.2.3
Flow capacity time series
Supply connections may be assigned a flow capacity [Volume per time] that
can never be exceeded.
To add a flow capacity time series, enable ‘has flow capacity’, click the
button and click Browse... to select an existing flow capacity time series or
click Create a new file… to open the ‘Create a new file’ dialogue.
The flow capacity overrules all other rules that may try to force more water
through the supply connection.
Example
A water user may call for 5 m3/s. If the flow capacity of the supply connection
has been set to 4 m3/s for example, the user will only receive maximum 4
m3/s and hence suffer a deficit, even though there may be plenty of water at
the source.
If the flow capacity of a supply connection is reached, the model will attempt
to force the water in an alternative direction. If this is not possible, the simulation will terminate with a message.
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Water Users
8.3
Return Flow Connections
If return flow occurs from the Water user, a connection must be created
between the Water user and the return flow point (cf. Inserting a water user in
this Section).
Under the Return flows tab three types of attribute data can be specified:
8.3.1

Return flow time series

Flow loss time series

Flow capacity time series
Return flow time series
A return flow time series must be specified either by clicking the
button
and clicking Browse... to select an existing time series file or clicking Create a
new file… to open the ‘Create a new file’ dialogue. The return flow time series
may contain the item type Return flow fraction (the fraction of the delivered
water) or the item type Discharge (a specified return flow).
If the return flow is given as a discharge, this discharge cannot exceed the
amount of water delivered to the user. A warning message will be issued if
the return flow must be reduced.
Multiple return flow points
The total return flow cannot exceed the delivered amount to the water user. If
there are multiple return flow points all given as a fraction of the delivered
water, the sum of the return flow fractions given in the return flow time series
should not exceed 1.0. It is possible, however, to have a sum less than 1, with
the remainder showing in the results as “Used Water”. The same apply if the
sum of return flow as discharge is lower than the delivered water.
If the sum of the return flow should exceed the amount of water available at
the user, the individual return flows will be reduced in the opposite order of
the list in the return flow connections table. In other words, the last return flow
listed, will be the first one being reduced in order to match the amount of
water available at the node.
8.3.2
Flow loss time series
Return flow connections may lose water due to seepage and /or evaporation.
If these processes are considered to be of importance they may be included
in the model as a time series that specifies the losses. Both seepage and
evaporation can be specified as a fraction of the actual flow (dimensionless),
or as flux (volume per time).
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Irrigation Scheme
To add a flow loss time series, enable ‘has flow loss’, click the
button
and click Browse... to select an existing flow loss time series or click on Create a new file… to open the ‘Create a new file’ dialogue.
If groundwater is defined in the catchment where the return flow point is
located (where the return flow connection terminates) seepage loss is added
to this groundwater storage.
8.3.3
Flow capacity time series
Return flow connections may be assigned a flow capacity [Volume per time]
that can never be exceeded.
To add a flow capacity time series, enable ‘has flow capacity’, click the
button and click Browse... to select an existing flow capacity time series or
click on Create a new file… to open the Create a new file dialogue.
The flow capacity overrules all other rules that may try to force more water
through the connection.
If the flow capacity of a return flow connection is reached, the model will
attempt to force the water in alternative direction. If this is not possible, the
simulation will terminate with a message.
8.4
Irrigation Scheme
The Irrigation scheme tab includes definition of three types of information:
8.4.1

Climate model

Deficit distribution method

Use a soil and runoff model for all fields
Climate model
The Climate model accepts a number of commonly available climate inputs
and converts them into precipitation and the input required by the reference
ET model, according to the selected Climate model.
Two Climate model types are currently available:


Rainfall only. This is the simplest climate model, only requiring a Rainfall time series and a reference ET time series as input.
FAO 56. The FAO 56 model requires the specification of Climate time
series as input for the calculation of the FAO 56 reference evapotranspiration.
The required inputs are:
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Water Users




Rainfall time series. A rainfall data time series is required for both the
Rainfall only and the FAO 56 models.
Climate time series. Climatic data are required input when the FAO 56
model is selected. The climate time series must include Relative humidity, Air temperature (min and max), Wind speed and Sunshine hours.
Coordinates. When the FAO 56 Climate model type is selected, the Latitude and Altitude of the location of the irrigation water user are required.
These coordinates will be set automatically if a coordinate system is
defined for the features (cf. 5.1 Coordinate System (p. 55))
Disaggregate rainfall. If rainfall is provided on a low temporal resolution
(e.g. monthly data), functionality to disaggregate the data into a higher
temporal resolution is provided. Checking the ‘Disaggregate rainfall’
checkbox enables the field where the new aggregation period can be
specified. Setting the time span to 10 days, for example, results in a rain
event every 10 days, of a magnitude that corresponds to:
–
–

8.4.2
Rain depth = (Aggregation period) / (Input time step) * (Rainfall
depth for input time step)
Disaggregation of rainfall is possible for both the Rainfall only and
the FAO 56 climate model.
Reference ET time series. When the climate model type is Rainfall only,
the time series of reference evapotranspiration must be entered. If the
FAO 56 model is selected, the reference ET is calculated according to
the FAO 56 method (see Appendix A.3 for additional details).
Deficit distribution method
Deficit distribution methods are used when the irrigation demand exceeds the
available water at the sources. In such cases, the deficit distribution methods
describe how the available water should be distributed among the fields represented by the node. When the deficit distribution method is selected, the
fields that are a part of the Water user need to be defined in the section Water
users  Irrigated field (cf. Section 8.5).
Three options are available:


110
Equal shortage. The fields get the same percentage of the demand covered, and hence suffer the same relative shortage.
By priority. The water is distributed according to the priority that has
been specified for the field. The fields with the highest priority (lowest priority number) will receive the full demand first. If several fields have the
same priority, water is distributed according to the equal shortage
method. The priorities are specified in the Irrigated field section.
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Irrigated Field

8.4.3
By Ky. This method is also called yield stress deficit distribution, since
the water is distributed according to how sensitive the crops are to soil
water stress at the time of water shortage. This implies that the crop with
the highest yield response factor (Ky) will be given the highest priority. In
case of several crops with the same yield response factor, water is distributed among these fields according to the equal shortage method. The
yield response factor of the crops is specified in the Crops module.
Use a soil and runoff model for all fields
If this option is selected, it is possible to specify in the dedicated box a Soil
and Runoff model that will be applied to all fields in the irrigation scheme
(unless a specific model has been selected for a field, see Section 8.5).
8.5
Irrigated Field
An irrigation Water user has one or more irrigated fields. Each irrigated field
consists of a sequence of crop shifts (a crop sequence). A crop shift is characterised by a starting date (sowing date), a crop, and a reference to the irrigation method that will be used to irrigate the crop. A crop shift lasts until the
end of the last growth stage of the crop in the field.
In the Irrigated field section, the crop sequence for each field has to be specified.
Each row added to the Irrigated field tab represents one of the crops growing
on the field in a particular period and on a specific area of the field. An irrigated field for a specific crop is defined by various properties, such as the
name of the crop, the area of the field, the properties of the soil in the field
and its ability to generate runoff.
The buttons at the bottom of the Irrigated field table can be used to add, or
delete the input for the different irrigated fields of the water user node. A field
is added to the Irrigated field node by clicking the ‘Append’ button ‘+’, which
results in a line being added to the Irrigated fields table. To delete a field,
select the field’s line and click Delete ‘-’: . The properties of the field can be
edited directly in the table.
Some attributes of the field are visible on the row of the specific field in the
field’s tab and they must be specified. These are:


ID. The field identification code, ID, is automatically given every time a
new field is added to the model.
Name. This corresponds to the name of the selected crop grown in the
field is entered.
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




Priority. If ‘by priority’ has been selected as deficit distribution method in
the Irrigation scheme section, priority is an integer defining the priority
with which the different fields will receive water in condition of scarcity.
The fields with the highest priority (lowest priority number) will receive
the full demand first.
Area. Size of field growing with specified crop.
Min. cycle time. The so-called minimum cycle time, expressed in days,
is an important parameter, if the farmer cannot irrigate the whole field
within a single time step, but in multiple time steps. In this case, sections
of the field will be created accordingly. Hence, soil moisture, and consequently yield, may be different on the different field sections and internally these are treated as different fields. In each output time step, the
average field conditions are written to the result file. To disable the minimum cycle time, set it to a value less than the simulation time step.
Example: If, for instance, it takes a farmer two days to irrigate the entire
field and the time step of the simulation is one day, then the field is
divided into two field sections and on the first day he irrigates one half
and the next day the other half.
Recycle crop sequence. If the same sequence of crops is cultivated in
the field, this box should be ticked. The frequency with which the crop
sequence is recycled depends on the total length of the crop sequence.
If the sowing years of the different crops differ, the sequence is repeated
as soon as the last crop is harvested and a new year starts.
Soil and Runoff model. Here, the appropriate Soil and Runoff model for
the crop of interest can be selected. By clicking on the box, the list of the
available models appears. The available models are those entered in the
section Irrigation data  Soil and runoff.
When clicking on the arrow next to the field’s ID, the tab expands and more
attributes of the field appear, which also have to be specified. These are:




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Crop model. The Crop model can be chosen from those entered in the
section Irrigation data  Crops (to jump to this section, right click on the
specific crop’s line in the tab and select ‘Go to Crops’). To select the
model, click on the Crop model field and the available option will appear.
Sowing year. The first sowing year for the crop has to be specified.
Irrigation method model. The Irrigation method can be selected from
those entered in the section Irrigation data  Irrigation method (to jump
to this section, right click on the specific crop’s line in the tab and select
‘Go to Irrigation method’). The list of the available models appears when
clicking on the Irrigation method model box.
First sowing date. This field displays the date when the crop is sowed
for the first time, given in dd-mm-yyyy format. This field cannot be edited.
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Irrigation Data

8.6
First harvest date. This field displays the date when the crop is harvested for the first time, given in dd-mm-yyyy format. If a crop is harvested before the next crop is planted, the model assumes that there are
no crops at this field in the time between crops, and hence that the irrigation demand is zero. When the next crop is sowed the water content in
the root zone will be reset to the initial water content, as specified in the
soil water model. This field cannot be edited.
Irrigation Data
Irrigation data comprise a variety of definitions related to Water users defined
as Irrigation type of users.
Regular water users and Irrigation water users functions very similar. The
main difference being that the Regular water user works on prescribed
demands and return flows, and the Irrigation user calculates the two variables
dynamically. An Irrigation water user represents one irrigation area comprising one or more irrigated fields, which are all drawing water from the same
sources. Each Irrigation user therefore represents the total irrigation demand
for all fields defined for this specific user.
The calculation of water demand and return flow for irrigation users are based
on detailed information about the soil and runoff properties of the fields as
well as the type of crop grown within these fields. Generally, several fields in
a basin model have the same soil properties and eventually identical type of
crops and the Irrigation Data entry enables the definition of specific croptypes, Irrigation method definition as well as overall Soil and runoff methods
that can then easily be applied when defining the specific details for Irrigation
Users within the Water Users page.
Irrigation data includes sub-pages for definition of:
8.6.1
Irrigation method
The Irrigation method section is used to specify how and when a given field is
irrigated.
A Name should be specified for each irrigation method. A new method is created by clicking on the ‘Append’ button, designated with the symbol . A
new line is then added to the tab displayed at the bottom of the page and the
input for the new method can be filled in.
Alternatively, predefined irrigation methods can be loaded from a template file
by clicking on the ‘Load template’ button,
, and browsing to the specific
template file. An existing template used in another MIKE HYDRO model can
also be used, by clicking on ‘Import existing’,
, and browsing to the previously created .mhydro file.
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By clicking on the ‘Delete’ button,
method is deleted.
, the currently displayed Irrigation
To switch between the different Irrigation methods, click on the lines relative
to different methods in the tab in the lower part of the Tabular view.
Type of irrigation methods
The following three Irrigation methods are available:

None (No irrigation method)

FAO 56 irrigation method

Rice Crop irrigation method
The Irrigation method dialogue also contains fields to set the Spray loss time
series, the Wetting fraction time series, the Trigger option and the Application
option. The Trigger option determines when the irrigation will start and the
Application option determines how the depth is calculated when the irrigation
has started.
The available options for Trigger and Application options depend on the
selected Irrigation method, while the Spray loss and the Wetting fraction time
series do not.
All input are specified as time series where the time is relative to the day of
sowing.


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Spray loss time series. The Spray loss time series correspond to the
fraction of the irrigation water that is evaporated before the water
reaches the soil surface. For sprinkler irrigation, this fraction may be relatively high, whereas it is relatively low for drip irrigation, for example. The
value has to be strictly less than 1.
Wetting fraction time series. The irrigation model requires a wetting
fraction that determines the fraction of the field surface that is being wetted during irrigation. For example, sprinkler irrigation this fraction will be
close to 1, whereas for drip irrigation it may be as low as 0.1. The wetting
fraction is also an important factor for determining how much irrigation is
required before the surface soil storage is filled and hence when the root
zone starts to fill.
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Irrigation Data
Figure 8.3
Illustration of the wetting fraction (after /1/) where I and Iw are the irrigation depth for the field and the irrigation depth for the part of the wetted
surface, respectively, and fw is the fraction of the surface wetted by irrigation
None (No irrigation method)
When this option is chosen, no irrigation is applied to the fields.
FAO 56 irrigation method
For the FAO 56 irrigation model the following parameters have to be specified
for the Trigger and Application options.
Trigger option

Option. The following four alternatives are available in the Trigger option
of the FAO 56 irrigation method:
–
–
Fraction of TAW (Total Available Water). Irrigation starts when the
soil moisture content reaches the specified fraction of TAW. TAW is
defined as the volume of water contained in the root zone when at
field capacity.
Fraction of RAW (Readily Available Water). Irrigation starts when
the soil moisture content reaches the specified fraction of RAW.
RAW is defined as the volume of water that can be transpired by the
crop without exposing the crop to soil water stress. It is defined as:
RAW = p  TAW
where p is related to the crop model (see more details in the Depletion fraction section, presented in the Crops section).
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–
–

Specified depletion depth. Irrigation will start when the soil moisture content reaches the specified depletion depth.
Prescribed. No Time series in the Trigger option box are required
as input when this option is selected. Irrigation is only described by
the irrigation Application option time series given as Fixed irrigation
rate option.
Time series. The Trigger option values are given as time series when
any other Trigger option than the Prescribed Depletion is selected.
Depending on the selected Trigger option, the required time series file
must contain:
–
–
–
Time in the first column, which indicates the number of days from
start of crop season, and either
Fraction [-], which is used for the first two options above, or
Depletion [mm], which is used for the specified depletion option.
Application option

Option. The following three alternatives are available in the Application
option of the FAO 56 irrigation method:
–
–
–

Fraction of TAW. Irrigation stops when the soil moisture content
reaches the specified fraction of TAW.
Fraction of RAW. Irrigation stops when the soil moisture content
reaches the specified fraction of RAW.
Fixed Irrigation Rate. The specified irrigation rate is applied to the
field.
Time series. The Application option values are given as time series.
Depending on the selected application option, the required time series
file must contain:
–
–
–
Time in the first column, which indicates the number of days from
start of crop season, and either
Fraction [-], which is used for the first two options above, or
Irrigation rate [mm/h], which is used for the specified depletion
option.
Rice Crop irrigation method
For the Rice Crop Irrigation model the following parameters have to be specified for the Trigger and Application options.
Trigger option

Option. The following two alternatives are available in the Trigger option
of the Rice Crop irrigation method:
–
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Prescribed. No Time series in the Trigger option box is required as
input when this option is selected. Irrigation is only described by the
irrigation Application option time series given as Fixed irrigation rate
option.
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Irrigation Data
–
Water Depth. Irrigation starts when the water depth on the ground
surface reaches a certain depth.
Application option

Option. When the irrigation is triggered, the application depth is calculated according to the Application option. The following options are available:
–
–
Fixed irrigation rate. Specified irrigation rate is applied to the field.
Fraction of Ponded Water Depth: Irrigation stops when the water
depth reaches the specified fraction of Maximum Water Depth
(MWD). Note: This option is not compatible with Prescribed Trigger
option.
The FAO 56 Irrigation method is also compatible with the Rice Crop model.
The Rice Crop irrigation method, however, is only compatible with the Rice
Crop model.
8.6.2
Crops
Given the soil moisture content and reference evapotranspiration, the crop
module takes the input to calculate the corresponding crop evapotranspiration and soil evaporation.
To create a new model click on the ‘Append’ button, designated with the symbol
. A new line appears in the window displayed at the bottom of the
screen. A Name should be specified by for the crop type. The inputs related
to the crop of interest can be entered in the boxes of the Crops section.
Alternatively, predefined crop models can be loaded from a template file by
on the ‘Load template’ button,
, and browsing to the specific template file.
An existing template used in another MIKE HYDRO model can also be used,
by clicking on ‘Import existing’,
, and browsing to the previously created
.mhydro file.
To delete the currently displayed crop type information click on ‘Delete’:
.
To switch between the different Crops models, click on the lines relative to different crop types in the tab in the lower part of the Tabular view.
Type of Crop models
Two different Crop model types are currently available:

FAO 56 DualCropCoefficient model

Rice Crop model
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FAO 56 DualCropCoefficient model
The FAO 56 method is based on the dual crop coefficient method described
in FAO 56. The FAO 56 DualCropCoefficient model calculates the transpiration and soil evaporation separately and thus allows for a more accurate
quantification of the consequences of using different irrigation technologies.
Following the FAO 56 terms, the Crop stages are divided into the following:

Initial

Development

Mid season

Late season
The parameters to be assigned to each Crop stage are:



Length. The length, in days, of the specific period.
Kcb. For each stage, a so-called basal crop coefficient (Kcb) is
assigned. The basal crop coefficient is defined as the ratio of the crop
evapotranspiration over the reference evapotranspiration (ETc/ET0)
when the soil surface is dry but transpiration is occurring at potential rate.
Kcb is assumed constant in the initial and middle stages, and assumed
to follow a linear variation between the stages.
Root depth. The Root depth R determines the maximum depth from
which the crop can extract water. The minimum and maximum depth has
to be specified. It is assumed that the maximum depth is obtained at the
beginning of the middle stage, and that the variation between the initial
depth and the maximum depth is determined by the following relationship:
 K cb – K cb ini 
-   R max – R min  + R min
R = ------------------------------------------- K cb mid – K cb ini 
where:
Kcb,ini : Initial crop basal coefficient [-]
Kcb,mid : Basal crop coefficient in middle stage [-]
R : Maximum root depth [m]
R : Minimum root depth [m]

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Max height. The influence of the vegetation surface roughness on the
evapotranspiration is taken into account through a climatic correction
factor applied to the basal crop coefficient. The vegetation height is
assumed to scale with the basal crop coefficients and is calculated as:
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Irrigation Data
 K cb – K cb ini 
-  H max
H = ------------------------------------------- K cb mid – K cb ini 
for the initial and development stage, after which the height is assumed
to have reached its maximum (Hmax).


Length (Yield). When the FAO 33 yield model is applied, each stage is
assigned a length that may, but does not have to, be the same as the
growth stages in the Crops model to which it is related.
Ky. Yield response factor that must be specified when the FAO 33 yield
model is applied. A crop is usually sensitive with different intensities to
soil moisture stress at different stages of its development.
Rice Crop model
For the Rice Crop model, one additional stage has been included: the Nursery phase. This stage is the period in which the rice plants are developing
before transplantation.
The supplementary inputs for the Nursery stage are:



Length. In days.
Nursery area. It is the ratio of the total field area in which Nursery takes
place. This is usually a small part of the future rice field.
Land preparation. The Land preparation stage is the period, expressed
in [days], before transplanting (at the beginning of the Initial stage). During this period the land is irrigated and the soil is puddled.
Note: As the Nursery stage also covers the Land preparation, the Nursery
period should be longer than the Land Preparation period.
Growing period
In this section two inputs should be specified:


Sowing day/month. The starting date (sowing date) of the shift of the
specific crop.
Last irrigation day. The irrigation can be stopped after a specified day.
This is a useful option when irrigation demand is calculated by the
model.
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Yield

Depletion fraction. The depletion fraction p expresses the sensitivity of
the crop to soil moisture stress, or more specifically, the fraction of the
totally available water (TAW) at which soil moisture stress will start to
reduce crop transpiration. The amount of water that may be depleted
without stressing the plant is called the readily available water (RAW).
The relationship between RAW and TAW is:
RAW = p  TAW
For soil moisture contents below RAW, transpiration is assumed to
decrease linearly with soil moisture content and reach zero when the
wilting point is reached (see Figure 8.4).
Figure 8.4
Relationship between RAW and TAW (after /1/)
Attaching a Yield model to a crop model allows the conversion of soil water
stress into the corresponding yield loss, and hence, to quantify the costs of a
soil moisture deficit.
One single yield model is currently available:

FAO 33 Yield model
The following three options are available for the FAO 33 Yield model:
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


Calculate yield. By ticking this box a yield model is attached to the crop
model. When choosing this option, the Potential yield can be entered and
so the Ky parameters for the different crop stages.
Potential yield. This parameter, expressed in [kg/ha], represents the
crop production per unit area of cultivated field and it must be entered
when the yield model is included.
Use yield stage length. Ticking this box enables the user to specify the
length of the periods with different Ky in the Length (Yield) section. These
may differ from the crop stage given in the Length section.
Note: The total length of the Length (Yield) periods has to be equal to
the total length of the Length periods (without including Nursery).
8.6.3
Soil and runoff
In the Soil and Runoff section, the parameters for different combinations of
soil type and runoff models are specified.
To create a new model click on the ‘Append’ button, designated with the symbol
. A new line appears in the window displayed at the bottom of the
screen. You can specify a Name for the new soil type, i.e. the name of the
dominant soil type in the soil profile. The Soil model and Runoff model inputs
can be entered in the relative sections.
Alternatively, predefined soil and runoff models can be loaded from a template file by clicking on the ‘Load template’ button,
, and browsing to the
specific template file. An existing template used in another MIKE HYDRO
model can also be used, by clicking on ‘Import existing’,
, and browsing to
the previously created .mhydro file.
To delete the currently displayed crop type information click on ‘Delete’:
.
To switch between the different soil and runoff models, click on the lines relative to different crop types in the tab in the lower part of the Tabular view.
Soil model
The Soil model, also referred to as soil water model, keeps track of the water
flow between different layers in the soil profile and the time-varying water
content in each layer (see Figure 8.5). The main task of the soil water model
is to keep track of the amount of soil water available for soil evaporation and
crop transpiration at any time during the simulation. The soil water content
may also be used by the irrigation module to determine the irrigation demand.
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Figure 8.5
Schematisation of the Soil Water models. Each model uses
a different number of layers
You can chose between three soil water model types:



FAO 56 soil water model. The FAO 56 soil water model is a simple
water balance based model that follows the recommendations provided
in FAO 56 /1/ for use with the dual crop coefficient method.
ZIMsched soil water model. The ZIMsched soil water model is one step
more complex than the FAO 56 soil model. It simulates the water balance in the unsaturated soil column in three compartments, instead of
the two of FAO 56.
ZIMsched for Rice field soil water model. The ZIMsched for Rice field,
a soil water model for rice crops, is an extension of the ZIMsched model
with an additional storage on the ground surface. This allows water to be
stored on the ground surface during growth of rice.
See ‘Irrigation’ (Section A.3) in Appendix A for more detailed information on
these models.
FAO 56 soil water model
In the FAO 56 soil water model dialogue, the required soil properties are
defined, and, here, the following parameters need to be specified (see also
Table 8.1 for suggested representative values):
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Soil moisture contents

Initial. This is the starting soil moisture content at the beginning of the
crop season [0-1]. The Initial soil moisture content is set for the Top soil
and the Root zone. For the Lower zone the initial soil moisture is by
default, at Field capacity.


Field capacity. This is the maximum water content held by the soil
against gravity [0-1]. Water cannot be retained in the top soil and the root
zone layer when the water is above field capacity, as it will drain away
under gravity. Soil moisture below field capacity is available for evapotranspiration until the soil moisture reaches wilting point.
Wilting point. This is the lowest soil moisture content at which plants
can draw water from the top soil and the root zone layers [0-1].
Other parameters are:


Porosity.This is the maximum soil moisture content that the soil can contain [0-1].
Depth of evaporable layer. This is the depth of the top soil layer from
which evaporation occurs [m].
Example
The amount of water in a soil column depends on the soil moisture content
and the length of the soil column. If the field capacity is 0.15, the wilting point
is 0.05, and the length of the root zone is 0.5 meter, then the available
amount of water for transpiration is: 500 mm.
Table 8.1
The representative soil property values and maximum depletion by
evaporation for an evaporation layer of 0.1 m
Soil type
Field capacity Wilting point
Difference
Max.
depletion by
evaporation
[mm]
Sand
0.07-0.17
0.02-0.07
0.05-0.11
6-12
Loamy sand
0.11-0.19
0.03-0.10
0.06-0.12
9-14
Sandy loam
0.18-0.28
0.06-0.16
0.11-0.15
15-20
Loam
0.20-0.30
0.07-0.17
0.13-0.18
16-22
Silt loam
0.22-0.36
0.09-0.21
0.13-0.19
18-25
Silt
0.28-0.36
0.12-0.22
0.16-0.20
22-26
Silt clay loam
0.30-0.37
0.17-0.24
0.13-0.18
22-27
Silt clay
0.30-0.42
0.17-0.29
0.13-0.19
22-28
Clay
0.32-0.40
0.20-0.24
0.12-0.20
22-29
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ZIMsched soil water model
The parameters for the ZIMsched soil water model are the same as those of
the FAO 56 model. Additionally, two extra parameters need to be specified:


Sat. hydraulic conductivity. The saturated hydraulic conductivity is also
called the saturated drainage coefficient [mm/h]. Since it is known that
the drainage of water from an unsaturated zone diminishes with diminishing soil moisture, water may not drain instantaneously from the time
when the water is above field capacity. In such cases water will be available for transpiration for a short period depending on the magnitude of
the saturated drainage coefficient.
Depth to groundwater. The unsaturated soil zone extends from the
ground surface to the groundwater table [m]. Based on the depth of the
top soil and the root zone layers, the lower soil layer can be calculated.
From this zone deep percolation to the groundwater takes place using
the same drainage formula as for the root zone layer.
ZIMsched for Rice field soil water model
The ZIMshed for Rice field soil water model requires an extra parameter
describing the maximum water depth that can be stored on the ground (often
called detention storage):

Max water depth. The maximum water depth [m] specifies the maximum water depth that can be held back on the ground surface before
surface runoff takes place. From this storage water can evaporate and
infiltrate into the top soil storage.
Runoff model
When it rains on the ground surface, a certain amount of the water may run
off, either as surface flow or as subsurface flow or both. The percolation to
groundwater is calculated whether a surface runoff model is included or not.
The task of the Runoff model is to calculate the surface flow part of the total
runoff. Surface runoff may occur either when it rains, when the crop is overirrigated, or when a combination of both happens (more details about the
Runoff Model can be found in Appendix A, Section A.3.5).
When the runoff model option is selected, an ‘f’ direct surface flow runoff is
calculated and subtracted from the rainfall. The remaining rainfall (called the
net rainfall, PN) is input to the soil column water balance. If PN together with
the applied irrigation cannot be stored in the soil (or on the ground surface, in
case of rice fields), additional surface flow runoff may occur. If the irrigation
node is connected to the river network, the calculated surface runoff will
return through the return flow channel to the river. If the irrigation node is not
connected to a river with a return flow channel, the water will be lost from the
model.
When the runoff model option is not selected, the total rainfall enters the soil
column water balance. If the rainfall and/or the irrigation input cannot be
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stored in the soil surface (or on the ground surface, in case of rice fields), the
surplus water is considered surface runoff and removed from the field. However, the surface runoff is not returned to the river, but lost from the model,
even if the irrigation node is connected to a river with a return flow channel.
There are four Runoff model options available:




None
Linear runoff model, available for all crops (i.e. for all types of Soil
model)
Modified SCS runoff model, available for all crops except rice (i.e. for
all types of Soil models except the ZIMsched for Rice field)
Modified SCS for Rice field runoff model, available only in combination with the ZIMshed for Rice field Soil model
None (No runoff model)
If the ‘None’ runoff model is selected, the rainfall enters the soil column water
balance. if rainfall and/or irrigation cannot be stored in the soil surface, the
surplus water is removed from the field and the model.
Linear runoff model
The Linear runoff model assumes a linear relationship between the rainfall
[mm] and the amount of surface runoff. The runoff will be generated according to two specified linear formulas, valid when the accumulated rainfall is
above or below a given threshold.
The parameters for the linear runoff model are:

When Rainfall is lower than. It is the threshold of the accumulated rainfall [mm] on the field below which runoff occurs. In this case the runoff
follows the formula specified in the line below:
Runoff = linear coefficient [ ] (fraction to be inserted in the formula) x
Rainfall + constant (to be inserted in the formula) in [mm]

When Rainfall is greater than. It displays the threshold of the accumulated rainfall [mm] on the field above which runoff occurs. If the rainfall is
above the threshold, the runoff follows the formula specified in the line
below:
Runoff = linear coefficient [ ] (fraction to be inserted in the formula) x
Rainfall + constant (to be inserted in the formula) in [mm]
Regardless of the specified parameters, the runoff will never be negative.
Note: When including the Linear runoff model, for any crop including rice, setting both coefficients in the linear equation to zero will have the same effect
as not including a surface runoff model. In that case, any excess surface
water will to return to the river.
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Modified SCS runoff model
When the Modified SCS runoff model is selected, the surface runoff is estimated using the Soil Conservation Service (SCS) storm flow equation
(USDA, 1985) /2/ as modified by Schulze (1995) and used in the ACRU agrohydrological simulation model in South Africa (cf. Modified SCS under Section A.3.5.2 in Appendix A for further details).
The parameters to be specified for the Modified SCS runoff model are:


Soil moisture integration depth. The soil moisture integration depth
[m] which has an influence on the infiltration losses in the modified SCS
model.
Coefficient of initial abstraction. This coefficient determines also the
infiltration losses.
Modified SCS for Rice field runoff model
The input parameters for the Modified SCS for Rice field runoff model are the
same as those for the Modified SCS.
The difference between the Modified SCS for Rice field model and the Modified SCS model is that the space (storage) between the maximum ponded
water depth (see the ZIMsched for Rice field model section) and the actual
water depth is also taken into account in the calculation of the water volume
of the potential maximum water retention of the soil, S.
In addition, excess water above the maximum ponded water depth at the end
of a time step is added to the already calculated surface runoff (this can only
occur when a specified irrigation application is used).
8.6.4
126
References
/1/
Allen, R.G., Pereira, L.S., Raes, D. and Smith, M., 1998. Guidelines
for computing crop water requirements. FAO Irrig and Drainage
Paper No. 56, FAO, Rome, Italy.
/2/
USDA, 1985. National Engineering Handbook, Section 4, Hydrology. United States Department of Agriculture (USDA), Soil Conservation Service, Washington DC, USA
MIKE HYDRO - © DHI
9
Reservoirs
The Basin module accommodates multiple multi-purpose Reservoir systems.
Individual Reservoirs can simulate the performance of specified operating
policies using associated operating rule curves. These define the desired
storage volumes, water levels and releases at any time as a function of current water level, the time of the year, demand for water, and losses and gains.
For Reservoirs, which have a significant surface area compared to the catchment area, in which they are located, it may be important to extract the reservoir surface area from the catchment area. This is done by enabling ‘Subtract
area of irrigation users and reservoirs from catchment area to calculate runoff’ in the Simulation specifications|modules page.
Note that in order to use this option the Reservoir must be located on the
catchment node.
Inserting a reservoir
To insert a Reservoir in the model select the ‘Add’ button under the Reservoirs ribbon in Map view and click on the desired location of the Reservoir.
The Reservoir must be located on a river Branch.
Figure 9.1
Inserting a Reservoir
The Reservoir may be connected to other Reservoirs and/or Remote flow
control points by using the ‘Add Connection’ button. The digitisation of a Connection must always be done in the direction of the flow.
Note that the mouse cursor changes to a cross when the cursor is properly
placed.
Specifying reservoir properties
The Reservoir properties dialogue contains the following tabs:

General

Operations

Users
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Reservoirs
9.1

Remote Flow Control

Storage Demand

Spillways
General
Under the General tab five reservoir properties are specified:
9.1.1

Reservoir type

Level-area-volume (LAV) table

Characteristic levels time series

Losses and gains time series (optional)

Sediment distribution type
Reservoir type
Three types of storage/reservoirs can be modelled and the input requirements will depend on the reservoir type selected:



Rule curve reservoirs regard the reservoir as a single physical storage
and all users are drawing water from the same storage. Operating rules
for each user apply to that same storage and the users compete with
each other to fulfil their water demand.
Allocation pool reservoirs also have physical storage, but the individual users have been allocated certain storage rights within a zone of
water levels. An accounting procedure keeps track of the actual water
storage in individual pools allocated for water supply users and in a single pool for downstream minimum flow releases (water quality pool).
Thus, a particular water level is not uniquely related to a set of volumes
in all pools (one can ‘shift’ some volume from one pool to another without
any effect on water level).
Lakes are specific reservoirs for which no operation rules apply. The outflow from a lake can be restricted by a spillway relationship. If no such
relationship is given and the water level is at dead zone level (top of
dead storage), all inflow that is not allocated to water users will flow out
from the lake immediately. Lakes may be used to represent wetlands.
Note: When simulating systems with Reservoirs, it is recommended to use
small time steps (days). During large time steps, water levels might move
through several zones in the operating rule curves, making results inaccurate.
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General
9.1.2
Level-area-volume (LAV) table
Computing water levels in a Reservoir requires the relationship between level
(elevation/height), area and volume (LAV) to be known. This information must
be specified as a table in a file:
Click on the
button and click Browse... to select an existing LAV table or
click Create a new file… to open the ‘Create a new file’ dialogue.
The LAV table is checked for physical plausibility. Particularly, it should hold
that:
V  H  i + 1    V  H  i   + A  H  i     H  i + 1  –H  i  
(9.1)
Where i is the i'th value in the table of increasing water level elevations H. In
other words, for every step in elevation, the increase in volume should at
least be the base area (at the previous level) times the increase in height. A
smaller increase corresponds to a 'narrowing' Reservoir (as water level
increases). A warning is issued at the end of the simulation to a 'narrowing'
Reservoir is detected.
During the simulation, linear interpolations between the user-specified neighboring data triplets in the table is performed to arrive at a piece-wise linear
LAV function.
Note: If the calculated Reservoir water level is outside the range of tabular
values specified in a LAV file during a simulation, an error message will
appear on the screen. No extrapolation is carried out beyond the range of the
specified elevation values in the LAV file. If a preliminary simulation is nonetheless desired, a work-around is to specify the Reservoir level in the LAV
table to start at zero and end at a very high level. This will avoid the necessity
to extrapolate and thus avoids the error message.
9.1.3
Characteristic levels time series
The following characteristic levels in a Reservoir must always be specified:



9.1.4
Bottom level: the bottom of the Reservoir
Dead zone level: the minimum level from which water can be utilised
(Top of dead storage). If the water level is below this zone water can only
be lost due to evaporation or bottom infiltration.
Dam crest level: the highest water level in the Reservoir before spill
occurs. note that Dam crest level is not used for Lakes.
Losses and gains time series (optional)
The following three losses / gains time series can be included:
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Reservoirs

Precipitation

Potential evaporation

Infiltration
To include losses/gains, enable ‘Include losses and gains’, click on the
button and click Browse... to select an existing time series or click Create a
new file… to open the ‘Create a new file’ dialogue.
To create a file with non-uniform values, the file must first be created with a
uniform value and then edited in time series editor.
This is done by clicking
and selecting ‘Edit in time series editor’.
The losses/gains are included in the water balance calculations and the
actual loss/gain in each time step (in terms of volume per time unit) will
depend on the actual water level (and thereby surface area) in the reservoir
at that time step.
If groundwater is defined in a downstream Catchment, infiltration from the
Reservoir will be added to this groundwater. However, with the current implementation the Reservoir has to be a Catchment node as well. Therefore to
observe the infiltration from a Reservoir to groundwater, the Reservoir must
have an immediate upstream and downstream Catchment (and the latter
must have a groundwater model specified).
9.1.5
Sediment distribution type
(Only relevant if Reservoir sedimentation is included in the Basin modules.)
If reservoir sedimentation is included in Basin modules, the Reservoir must
be assigned a ‘sediment distribution’ type. The type depends on the shape of
the Reservoir as well as its operation. There are four types of reservoir
shapes and four types of reservoir operation (cf. Table 9.1).
Table 9.1
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Reservoir shapes and Reservoir operations
Reservoir shapes
Reservoir operations
Type I (Lake)
Type I (Sediment submerged – continuous high pool level)
Type II (Floodplain-Foothill)
Type II (Moderate drawdown)
Type III (Hill-Gorge)
Type III (Considerable drawdown)
Type IV (Gorge)
Type IV (Normally empty)
MIKE HYDRO - © DHI
General
The sediment distribution type is a weighted average of the reservoir shape
type and the reservoir operation type as shown in Table 9.2.
Table 9.2
Guide to selection of sediment distribution types
Operations type
Shape type
I
II
III
IV
Sediment distribution type
I
I
II
I or II
III
II
I
I or II
II
II
III
II or III
I
II
II
II or III
III
III
All
IV
Where a choice of two sediment distribution types is given, or in borderline
situations, the type should be selected according to whether reservoir shape
or operation is expected to be most influential. This selection may also be
guided by the sediment grain size, as shown in Table 9.3. However, in most
cases sediment grain size has been found to be the least important factor
influencing sediment distribution.
Table 9.3
Links between sediment grain size and sediment distribution type
Predominant grain size
Typical sediment distribution type
Sand or coarser
I
Silt
II
Clay
III
The sediment distribution type determines the formulas used to distribute the
sediment load within a Reservoir. Based on this, the level area volume (LAV)
curve is updated. The sediment distribution types reflect the tendency for
sediment in lake-type reservoirs to accumulate in shallower water and in
gorge-type reservoirs to accumulate in deeper water.
For more information, please refer to Morris & Fan (1997): Reservoir Sedimentation Handbook, McGraw-Hill, 1997, p. 10.32-10.39.
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Reservoirs
9.2
Operations
Under the Operations tab six different operating rules can be specified:
1.
Minimum release requirement (optional): release required to support
environmental flows in the river downstream of the reservoir. This
release takes place as long as the water level is above the Dead zone
level (Top of dead storage).
2.
Maximum release requirement (optional): a restriction on the flood control release when the water level in the Reservoir is above Flood control
level (or Spillway bottom level, if defined).
3.
Minimum operation level requirement (optional): the minimum level at
which water is supplied to water users. Below the minimum operation
level, only minimum flow requirements are released. If minimum operation level is not specified, the model uses the Dead zone level (Top of
dead storage) as the minimum operation level.
4.
Flood control level time series (mandatory): the level above which
water is released for flood control purposes.
5.
Guide curve level (optional only for allocation pool reservoirs): the level
below which the Reservoir is ‘divided’ into pools.
6.
Pool ownership for downstream river time series (mandatory only for
allocation pool reservoirs), cf. 9.3.3
All operation rules are specified as time series. This is done by enabling the
relevant operating rule (for optional rules) and specify the time series
by clicking on the
button and selecting Browse to include an existing time series or selecting Create a new file to open the ‘Create a new file’
dialogue.
Note that minimum and maximum release requirements may be influenced
by remote flow requirements (cf. Remote Flow Control).
Based on the rule curve levels and reservoir characteristics, Reservoirs can
be divided into different zones depending on the type of reservoir.
9.2.1
Lakes
All Lakes have an Inactive zone (Dead storage). If the Level-area-volume
(LAV) table includes levels above Dead zone level and a Spill capacity table
defined, Lakes also have an Inundation zone. In the Inundation zone excess
water may be stored. The highest level defined in the LAV table thus represents the ‘Dam crest level’ for Lakes. If no Spill capacity table is given and the
water level is at Dead zone level (top of dead storage), all inflow that is not
allocated to Water users will flow out from the Lake immediately.
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Operations
Figure 9.2
9.2.2
Zones in a Lake
Rule curve reservoirs
Rule curve reservoirs are divided into five zones as illustrated in Figure 9.3,
Figure 9.3
Operating zones in a Rule curve reservoir
Flood control zone
This zone serves as storage buffer to diminish the impacts of high floods.
Under normal circumstances the water level in the reservoir is kept at Flood
control level to maintain optimal protection and reserve water for supply. If the
water level is within the Flood control zone, water is released at a rate up to
maximum downstream release. The release can be limited by spillway conditions.
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Reservoirs
If a Spillway bottom level time series is specified (see the Spillways, Section
9.6) the lower level of Flood control zone is defined by the Spillway bottom
level, no matter whether this is above or below the Flood control level.
Normal operating zone
This zone is between the Flood control level (lower level of the flood control
zone) and the first Reduction level for a given water user. In the Normal operating zone all demands are fulfilled. The extend of this zone can vary for individual water users.
Reduced operating zone
If the water level is in this zone, a demand is only partially fulfilled. A variable
number of reduction level curves and corresponding reduction factors can be
specified for each connected water user as described in Section 9.3 ‘Users’.
The lower limit of the Reduced operating zone is the Minimum operation
level. If this level is not specified then the lower limit is the Dead zone level
(Top of Dead Storage).
Conservation zone
If the water level reaches this zone, only downstream release (minimum
release requirement for environmental flows is maintained). No water for
usage is being released. The Conservation zone only exists if a minimum
operation level has been specified.
Inactive zone (Dead storage)
If the water level reaches the Inactive (Dead storage) zone, water can only be
lost due to evaporation or bottom infiltration.
9.2.3
Allocation pool reservoirs
In Allocation pool reservoirs the main storage is divided into four zones as
illustrated in Figure 9.4:
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Users
Figure 9.4
Operating zones in an allocation pool reservoir
The Flood control zone and the Inactive zone are identical to those of a
Rule curve reservoir.
The Common allocation zone only exists if a guide curve level has been set
below a flood control level thus allowing storage of water between these two
levels. The guide curve corresponds to the top of the pool allocation zone.
The Pool allocation zone is divided into a pool for releases to the downstream river (sometimes called a ‘water quality pool’) and a number of water
supply pools defined by the user. All these pools are purely conceptual
accounting storages used internally in the program, and should not be
regarded as physical storages.
9.3
Users
Under the Users tab five types of attribute data are specified for each water
user connected to the reservoir:
9.3.1

Priority

Number of reduction levels

Pool ownership time series (only available for Allocation pool reservoirs)

Flow loss time series

Flow capacity time series
Priority
You can connect multiple Water users, Hydropower plants and Reservoirs to
a Reservoir. By default, connections are given a priority according to the
sequence in which they are digitised. The priority can be changed in the priority column. Number 1 has first priority; number 2 has second priority, and so
forth.
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Reservoirs
Note that the minimum release from the Reservoir always has a higher priority than all other users. In order for a user to effectively have first priority, the
specified minimum release for the Reservoir must be set to zero and there
must be no minimum remote flow requirements.
9.3.2
Number of reduction levels
You can specify operating rules for supplying water to the individual users.
This is done by specifying the No. of Reduction levels. For each Reduction
level a time series containing Reduction water levels and corresponding
Reduction factors must be specified.
Note that Allocation pool reservoirs have Reduction thresholds (fraction of
pool volume) instead of Reduction levels (reservoir water levels). Reduction
thresholds are specified in the same way as Reduction levels.
To specify Reduction level time series for a Water user, click on the small
arrow to the left of the Water user name. A grid cell then becomes available
for each Reduction level.
Click on the grid cell and a
grid cell.
button appears in the right-hand side of the
Click on the
button and click Browse... to include an existing time
series or click Create a new file… to open the ‘Create a new file’ dialogue.
Two items must be specified: Reduction level and Reduction fraction.
When the reservoir water level falls below Reduction level 1 for a specific
user, the actual extraction is calculated as the water demand times the specified Reduction factor 1. If the reservoir water level falls below Reduction level
2, a more drastic Reduction factor 2 is applied, and so on. Each user has its
own set of reduction levels and corresponding reduction fractions and can
have as many sets as required.
Figure 9.5 illustrates how different Reduction levels and factors can apply to
different Water users. In the figure, a low priority user (e.g. industrial production) is getting its demand reduced earlier and more drastically, than a high
priority water user (e.g. public water supply).
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Users
Figure 9.5
Illustration of reduction levels and reduction fractions for two users
Example:
Assuming two Water users extracting water from a Reservoir. The following
rules apply for the two water user nodes:
The demand for both Water user nodes is 13.89 m3/sec.Operating policy:

User node 1 (W4): Reduction level at:541 m, Reduction factor: 0.8

User node 2 (W6): Reduction level at 540 m, Reduction factor: 0.6
The initial water level in the Reservoir is 544 m, and the inflow is zero until the
20th January, where the inflow is 35 m3/s. Figure 9.6 illustrates how the water
level is falling as water is extracted from the Reservoir. When the water level
reaches level 541 m, the withdrawal by user node 1 is reduced to 80%, and
the water level falls with a lower rate. When the water level falls below level
540 m, the withdrawal to user node 2 is also reduced. Once the inflow to the
Reservoir starts the water level is rising with a reduced rate as the withdrawal
increases.
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Reservoirs
Figure 9.6
9.3.3
Water supply as a function of water level and reduction fractions
Pool ownership time series
(Only available for Allocation pool reservoirs).
Allocation pool owners can be Water users, Hydropower plants or other Reservoirs that extract water from the Reservoir. Additionally, the downstream
river ‘owns’ an allocation pool (sometimes called ‘water quality pool’) that
releases water to the downstream river. Pool ownership time series for the
downstream river is specified in the Operations properties dialogue (cf. Section 9.2).
To add pool ownership time series to a user click on the ‘pool ownership grid
cell’,
and a
138
button appears in the right-hand side of the grid cell.
MIKE HYDRO - © DHI
Users
Click on the
button and select Browse to include an existing time
series or select Create a new file... to open the ‘Create a new file’ dialogue.
Pool ownership time series must contain two items:

Fraction of total storage owned by that water user;

Fraction of inflow owned by that user.
Note that for both items the sum of the fractions owned by all users including
the downstream release should add up to 1.0.
9.3.4
Flow loss time series
Supply connections may lose water due to seepage and /or evaporation. If
these processes are considered to be of importance they may be included in
the model as a time series that specifies the losses. Both seepage and evaporation can be specified as a fraction of the actual flow (dimensionless), or as
flux (volume per time).
To add a flow loss time series, enable ‘has flow loss’, click on the
button and click Browse... to include an existing flow loss time series or click
Create a new file… to open the ‘Create a new file’ dialogue.
The user-specified water demand D of the connected user is automatically
adjusted to take the loss into account. The adjusted water demand D* is calculated as follows:
D
D* = ------------------------------------- 1 – loss factor 
(9.2)
This means that the Water user demands will still be fulfilled if sufficient water
is available in the Reservoir. This also applies if the flow loss is given as a
flux.
If groundwater is defined in the Catchment where the Reservoir is located the
seepage loss from the connection is added to this groundwater.
Note that if the Reservoir is located on a Catchment node, seepage loss is
added to the next downstream Catchment if a groundwater model is included
for that Catchment.
Note that for Water users, flow loss time series in supply connections may
also be specified in the dialoguedialog.
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Reservoirs
9.3.5
Flow capacity time series
Supply connections may be assigned a flow capacity [Volume per time] that
can never be exceeded. To add a flow capacity time series, enable
‘has flow capacity’, click on the
button and click Browse... to include an
existing flow capacity time series or click Create a new file… to open the ‘Create a new file’ dialog.
The flow capacity overrules all other rules that may try to force more water
through the connection.
Example
A Water user may call for 5 m3/s. If the flow capacity of the supply connection
has been set to e.g. 4 m3/s, the user will only receive max. 4 m3/s and hence
suffer a deficit, even though there may be plenty of water at the source.
If the flow capacity of a supply connection is reached, the model will attempt
to force the water in alternative direction. If this is not possible, the simulation
will terminate with a message.
Note that for Water users, flow capacity time series in supply connections
may also be specified in the Water user dialog.
9.4
Remote Flow Control
Remote flow controls are logical relationships between a Reservoir and one
or more flow control points downstream from the Reservoir, possibly with
many intermediate inflows and offtakes.
To connect a Reservoir to a remote flow control point, click the ‘Add connection’ button under the Reservoirs ribbon in Map view. Connect the Reservoir
to the desired downstream point (anywhere on downstream Branches, but
not Water users). A regular River node is automatically inserted on the
desired flow control point and adds the Remote flow control to the Reservoir
properties. A Reservoir can have multiple Remote flow connections.
Under the Remote flow control tab minimum or maximum remote flow
requirements can be specified.
To add a minimum or maximum flow requirement to a remote flow connection, enable ‘min. flow requirement or max. flow requirement’, click on
the
button and click Browse... to include an existing flow requirement
time series or click Create a new file… to open the ‘Create a new file’ dialog.
During simulation, MIKE HYDRO will try to adjust the reservoir releases to
meet the remote flow requirements after considering all inflows, extractions
and flow delays due to routing. If the adjusted minimum reservoir release (to
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MIKE HYDRO - © DHI
Storage Demand
meet the remote flow requirements) is higher than a specified minimum
release requirement for the reservoir, the adjusted reservoir release determines the actual minimum reservoir release. Similarly, if the adjusted maximum reservoir release (to meet the remote flow requirements) is lower than a
specified maximum release requirement for the reservoir, the adjusted reservoir release determines the actual maximum reservoir release.
9.5
Storage Demand
Under the Storage demand tab transfers between two Reservoirs can be
specified. The two Reservoirs must be connected by using the Add Connection button under the Reservoir ribbon in Map view to digitise the connection.
The digitisation of a connection is always in the direction of flow, i.e. from
‘upstream’ (supplying) reservoir to ‘downstream’ (receiving) Reservoir. In
order to model bi-directional transfers between two Reservoirs, two connections must be digitised – one in each direction.
Once the Reservoirs are connected, the connection will appear under the Priority tab for the ‘upstream’ (supplying) Reservoir and under the Storage
Demand tab for the ‘downstream’ (receiving) Reservoir. The storage demand
time series specifies the critical water level or water volume that must be
maintained in the ‘downstream’ (receiving) Reservoir.
To specify the storage demand time series, click on the
button and
click Browse... to select an existing time series or click Create a new file… to
open the ‘Create a new file’ dialog.
Note that for bi-directional transfers to be operational, the priority of the supply connections must be higher than that of any other user connected to the
Reservoir(s). Minimum flows still have higher implicit priority in that any minimum releases are performed before any transfer to users or other Reservoirs.
9.6
Spillways
Reservoir releases during flood control operations can be controlled by two
spillways:


A (top) spillway defined by the Spill capacity table Q(h) and the Spillway
bottom level time series, and
A (bottom) spillway, defined by the Bottom outlet capacity time series
Qb(t), often assumed to be located at the base of the dam.
For Lakes, only a Spill capacity table can be specified.
The spillway capacity is generally determined physically by water level (relative to the spillway base), and thus, must be given as an h-Q(h) table. The
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Reservoirs
bottom outlet's capacity, on the other hand, can usually be regulated, and
thus, must be given as a time series.
Spillway limitations can cause the water level in the Reservoir to rise above
Flood control level and even above the Crest level of the dam. The spillway
properties are specified in the Spillway tab. Other properties, which may
directly influence how spillways work, are the Flood control level and the
Maximum release requirement (specified under the Operations tab).
9.6.1
Spill capacity table
The (top) Spill capacity table is an h-Q table, where h is water level relative
(above) to the Spillway bottom level and Q(h) is maximum possible release
(volume/time) at that water level. The operating range for the top spillway is
between the Spillway bottom level and the Crest level.
The release through the spillway is the minimum of Q(h) and the Maximum
Release, if the latter is specified in the Operations tab.
9.6.2
Spillway bottom level time series
The Spillway bottom level time series describes the base level of the (top)
spillway and is used to calculate the relative water level h in the h-Q relationship defined above. The Spillway bottom level can be either above, below or
at Flood control level.
If this time series is not specified, the Spill capacity table will use the Flood
control level as the base level of the spillway and thus, use this level to calculate the relative water level h.
9.6.3
Bottom outlet capacity time series
Bottom outlet capacity is a capacity limitation time series Q(t). It is designed
to release/flush water from the lower part of the Reservoir, when the water
level is higher than the Flood control level. The operating range for the Bottom spillway is between Flood control level and Crest level.
If the Spillway bottom level time series are not specified, the Bottom outlet
capacity will be set to zero.
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Spillways
Figure 9.7
Spillway options
Both spillways may function simultaneously if the level in the Reservoir
exceeds both the Flood control level and the Spillway bottom level. If a Minimum release requirement time series has been specified in the operation
rules, this will be added to the total release.
If the release from the bottom spillway shall include the Minimum release
requirements at times when the water level in the reservoir is above the Flood
control level, then the Minimum release requirement time series should be
subtracted from the Bottom outlet capacity time series Qb(t).
Similarly, if the release through the top spillway should include the Minimum
release requirement at times when the water level in the Reservoir is above
the Spillway bottom level, then the h-Q(h) relationship should be adjusted to
include the Minimum release requirement.
Example
This example illustrates how the spillway functions work in a situation where
the Reservoir is emptied, and no inflow occurs. The Initial water level is 543
m and the Flood control level is 542 m. The Spillway bottom level is 541 m,
and the Bottom outlet capacity is 1.5 m3/s.
Figure 9.8 shows that the release through the spillways is the sum of spill
capacity (the Q(h) table) and the Bottom outlet capacity = 1.5 m3/s from initial
water level down to Flood control level. The release between Flood control
level and the Spillway bottom level (541 m) follows the spill capacity q(H)
table as the release from the Bottom outlet spillway is zero.
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Reservoirs
Figure 9.8
9.7
Calculation of outflow as a function of water level and spillway characteristics
Guide Curve Level (for Global Ranking)
When Global ranking has been selected as water allocation rule (see 11
Global Ranking (p. 153)), at least one Guide curve level must be defined for
each Reservoir. Otherwise, if no Guide curve level is defined for a Reservoir,
then the reservoir will not release any water at all (except for the basic reservoir operations).
A Guide curve level defines the level to which water may be released to meet
the water demand of a Water user (For Global ranking, Water users are
defined by the unique Ranking number of their Supply connections). The
Guide curve level must be defined above Dead zone level (or Minimum operation level if defined).
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Guide Curve Level (for Global Ranking)
Only Water users with corresponding Ranking numbers (priorities) for which
Guide curve levels are defined will receive water.
The reservoir will determine whether to release water for a given global ranking supply connection by verifying two conditions:
1.
The water level of the reservoir is above the water level stated in one of
the guide curve level for the current date (data given in a time series),
and
2.
The global priority of the supply connection to the water user is higher
(lower numerical value) than the priority level related to the same guide
curve level of the reservoir.
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Reservoirs
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10
Hydropower
MIKE HYDRO Basin can perform advanced hydropower simulations for
either existing systems or for evaluation of the feasibility of new developments. A Hydropower plant extracts water from one or more reservoirs, produces power according to effective head difference and power efficiencies,
and returns water to one or more downstream locations.
It is hence required to initially define at least one Reservoir in the model to be
able to connect and include a hydro power plant within the model setup (illustrated in figure below).
Figure 10.1
Hydropower plant defined with a single reservoir connection and return
flow definition to river location downstream of reservoir
Calculation of hydropower can include special options such as conveyance
and head losses as well as tail water level and backwater effects from cascading reservoirs.
Inserting a hydropower plant
Hydropower generation is simulated by inserting a hydropower plant and connecting it to a reservoir. Return flow back to the river is simulated by connecting the hydropower station to one or more downstream locations.
To insert a Hydropower plant, select the ‘Add’ button under the Hydropower
plants ribbon in Map view and click on the desired location of the Hydropower
plant in the map.
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Hydropower
Figure 10.2
Insert a Hydropower plant
Note that the location is for visual purposes only and has no impact on the
model setup.
The Hydropower plant is connected to the reservoir and the return flow point
by using the ‘Add Connection’ button under the Hydropower plants ribbon in
Map view.
Note: The formula used to calculate the hydroelectric power produced is
described in Appendix A (Equation (A.2.1) under A.2 Hydropower - Formula).
Specifying hydropower properties
In the Hydropower plants properties dialogue the following properties can be
specified:
10.1

Power Demand Time Series

Head Approximation

Use Minimum Release from Reservoir Option

Power Efficiency Table

Tailwater

Head Loss Table
Power Demand Time Series
The Power Demand time series file contains the four following items
148
1.
Target power. Target power demand, either as Target Power [MW or
equivalent] or as Water Flow [m^3/s or equivalent].
2.
Installed capacity, effective only when ‘Create item for surplus capacity
fraction’ is selected under the Surplus capacity fraction tab, but must
always be present and non-blank. Specified as Power [MW or equivalent] or as Discharge [m^3/s or equivalent].
3.
Fraction. Surplus capacity Usage [dimensionless]. Fraction between 0
and 1.
4.
Head difference. Minimum head for operation of turbines, specified as
Head Difference [m or equivalent]. If head (difference between reservoir
level and tailwater level or reservoir bottom level if no tailwater is
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Head Approximation
specified) drops below this threshold, no water is routed through the turbines, regardless of power demand.
The option to produce more power than demanded (up to installed engine
capacity) at times where there is a surplus of water in the Reservoir is applicable when the reservoir water level is above Flood control level. Water that
would otherwise be spilled can be routed through the turbines. Any release
that - due to limited turbine capacity - cannot be exploited for hydropower
generation is spilled from the Reservoir.
10.2
Head Approximation
Calculation of hydropower demands and actual generation is subject to
numerical inaccuracy when tailwater and/or power efficiency tables are used.
There are two approximations available


10.3
explicit method based on head in the supplying reservoir at the start of
the time step, or
time step average method based on the average head at start and end
of the time step.
Use Minimum Release from Reservoir Option
If this option is enabled the minimum release (as specified under the Operation tab in the Reservoir properties dialogue) is assumed to be routed through
the hydropower station/plant and to be contributing to the total flow necessary
for generating the required hydropower.
Note that this option must only be used when releases from the Hydropower
plant and releases from the Reservoir are routed to the same river.
Example
If the hydropower demand requires a discharge of 100 m3/s through the turbines and the downstream release has been specified as 10 m3/s. Enabling
this option will give a total release of 100 m3/s. If it is disabled the total
release will be 110 m3/s provided there are no restrictions in water delivery for
hydropower.
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Hydropower
10.4
Tailwater
Figure 10.3
Effective head as difference between reservoir water level and tailwater
level
Tailwater table
The Tailwater table specifies tailwater level as a function of release from the
reservoir.
To include a Tailwater table, enable ‘Use Tailwater table’ and click
browse to an existing table or to create a new table.
to
Note that a discharge-dependent tailwater level necessitates iterations in the
solution of the water allocation problem (demand becomes a function of tailwater level, which depends on reservoir release, which finally depends on
demand). Thus, for precise results, often a daily simulation time step should
be chosen in connection with hydropower simulations.
Use downstream release from reservoir
Besides the flow through the turbines other releases through spillways and
gates may contribute to the tailwater level. If this is the case, enable ‘Use
downstream release from reservoir’, and this flow together with the flow
through the turbines will be used to estimate the tailwater level in the Tailwater Table.
Backwater effects
In cascades of reservoirs, tailwater elevation for a hydropower station can be
determined by water level in the next reservoir downstream rather than by
discharge from the supplying (upstream) reservoir. If this is the case for a particular model, enable the ‘Has backwater from reservoir below’ option.
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Power Efficiency Table
10.5
Power Efficiency Table
The Power efficiency table specifies power (machine) efficiency as a function
of head difference or the discharge. When a Power efficiency table is used,
the Power Demand time series will be adjusted accordingly.
To include a Power efficiency table, enable ‘Use Power efficiency table’ and
click
to browse to an existing table or to create a new table.
Note that a head-dependent or discharge dependent efficiency necessitates
iterations in the solution of the water allocation problem (demand becomes a
function of efficiency, which itself depends on reservoir level, which again
depends on reservoir release, which finally depends on demand). Thus, for
precise results, a daily or shorter simulation time step should be chosen when
the Power efficiency table is used.
10.6
Head Loss Table
Significant head loss in hydropower systems can be caused by friction in the
pipes connecting reservoir and turbines (conveyance loss). This can be
included in the simulation by enabling ‘Use Head loss table’ and specifying
the head loss table (head loss h as a function of discharge Q) - by clicking
on the
button to select an existing table or to create a new table.
Specifications of a head loss table is optional, and if no table is provided,
head loss will not be taken into account.
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Hydropower
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Global Ranking Parameters
11
Global Ranking
Global ranking may be used to prioritise water allocation to Water users,
Hydropower plants and Reservoirs independently of their geographical location in the river basin.
When global ranking is selected, all other allocation rules/priorities are
ignored. This includes local priorities and Reservoir reduction levels.
Note: If Allocation pool reservoirs are included in the present version, they
will behave as Rule curve reservoirs when using global ranking.
Note: Routing and bi-directional connections cannot be used with the current
implementation of global ranking.
11.1
Global Ranking Parameters
When Global Ranking is selected, all supply connections in the model setup
automatically appear in the dialogue, and each supply connection must be
assigned a unique ranking number. The following overall conditions apply to
the Global Ranking feature:






Ranking numbers are float numbers
Ranking priority decreases with increasing ranking numbers.
That is, the supply connection with ranking number 1 has first priority, the
supply connection with ranking number 2 has second priority etc.
A ranking number is unique. Ranking numbers cannot be shared and
each supply connection must have a unique ranking number.
For Water users with more than 1 supply connection, consecutive ranking numbers may be assigned to ensure consistent priority.
All supply connections must be assigned a ranking number.
Only Reservoirs with defined Guide curve levels (pg. 144) will release
water to fulfil demands.
Note: Ranking numbers may be displayed in Map view by selecting ‘Ranking
number’ in the ‘Show label’ drop- down menu.
The Global Ranking algorithm
The global ranking allocation time step algorithm functions in the following
way:
–
First, it flushes all water due to natural causes for the given time
step. This includes runoff from catchments, minimum releases from
reservoirs, and bifurcated water flows.
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Global Ranking
–
–
–
–
At this moment it flags all flowing water as "Unallocated". The condition of unallocated water is very important for the global ranking rule,
because it is precisely what in principle allows water to be assigned
to a given water user, and therefore, at the beginning of a time step
algorithm, all available water in the network is unallocated, and
therefore can be assigned to any water user.
Then it starts making water assignments to the water users by the
global priority order of their corresponding supply connections.
Notice that the global priority is a property of each supply connection, and not of the water user (it is NOT the water user having a
global priority, but it is the supply connection between the river node
and the water user node having the global priority).
Once some water has been assigned to a water user through a
given connection, this water cannot be re-assigned to any other supply connection, even if it is located upstream (the algorithm does not
allow upstream water users to "steal" water from downstream water
users, because the water assigned to the downstream water user
has been flag as allocated).
The algorithm works in the way of iterating through all water users
(or more precisely, though all supply connections) in their global priority order until no more unallocated water is left.
This procedure is executed for every time step of the Mike Hydro simulation.
At the process of assigning water to a given user through a supply connection, the global ranking rule will assign as much water as to satisfy the water
user demand only limited by the either the unallocated water value, or if
exceeding this value, under the condition of not violating any assignment
already performed, and that this eventual excess of assigned water is compensated with the return flow of the same water user (considering that the
water user's return flows is new unallocated water to the river network). For
example, if a river node carries a flow containing 5 m3/s of unallocated water,
it may be entitled of allocation of, for instance 6 m3/s, as long as its return flow
is larger than 1 m3/s (as it would mean an net supply of 6 - 1 = 5 m3/s), and no
other water assignment has been carried within the reach between the supplying node and the return node. As a consequence, the final unallocated
water at the supplying node may become negative, in this case equal to (5-6)
m3/s = -1 m3/s. The -1 m3/s symbolises the temporal violation of the unallocated water constraint at the supplying node.
If this assignment is still not enough to cover the water user demand for the
current time step, the algorithm will search for the so called "Global Priority
Water sources" (GPW sources), which are sources that can provide extra
water to the river, and therefore extra unallocated water which could be
assigned to satisfy the water user needs.
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Global Ranking Parameters
These GPW sources can be of two types:
1.
Guide curve reservoirs
2.
Bifurcations.
When a water user does not get its water demand satisfied directly from the
river network, it will request the closest GPW source (after a conveniently
defined distance, counting the number of network nodes to the node supplying to the water user). A reservoir needs to be located upstream to the
demanding supply connection, while a bifurcation can be located upstream or
downstream, as long as it is located in the same branch as the demanding
supply connection (otherwise the source cannot provide unallocated water in
any way).
If the GPW source is a reservoir, this reservoir water is requested to release
water to the river network. The reservoir will provide the maximum available
water in order to satisfy the demand of the supply connection. The released
amount is determined by the "global ranking guide curve levels" of the reservoir. (See “Guide Curve Level (for Global Ranking)” on page 144).
Let us consider an example as illustrated in Figure 11.1.
Figure 11.1
Global ranking example
Water user 4 at the bottom of the network has the highest priority (Global Priority = 1) and a water demand of 10 m3/s. However, where the river is supply-
155
Global Ranking
ing river node (N11) the unallocated water is only 4 m3/s. Therefore, the
algorithm will request the reservoir upstream (node N1) to release the
remaining 6 m3/s, which will not be touched by any of the other water users in
the network (unless they have a return connection with return flow fraction of
1). However, there is a risk that this released water might get stuck at a downstream reservoir which is in a critical state and therefore holding the water
instead of releasing it.
If the GPW source is a bifurcation, the algorithm will change the distribution of
flows at this node, limited by the unallocated water amounts at each side of
the bifurcation. When some water is re-directed to the opposite sub-branch of
the bifurcation, a corresponding amount of extra unallocated water is placed
in the demanding sub-branch (i.e., the sub-branch where the demanding supplying connection is located), and therefore this extra water can be allocated
to the water user through the corresponding supply connection.
Let us consider simple bifurcation example (see Figure 11.2).
Figure 11.2
Global ranking example at bifurcation
Suppose a simple network with a bifurcation, where the water flow before
assignments is 10 m3/s and the bifurcation is set to a fraction of 0.5, or equivalent, 5 m3/s.
A water user is located at each side of the bifurcation, with respective global
priorities of 1 and 2 and demands of 7 m3/s and 5 m3/s. Without bifurcation
optimization, the bifurcated value would be of 5 m3/s. With these flows at
each side, the water user 1 (Global Priority = 1) would be able to obtain 5
m3/s and therefore have a demand satisfaction fraction of 5/7 (71.4 %), while
the water user 2 (with Global Priority = 2) will have a demand satisfaction of
5/5 (100 %).
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Global Ranking Parameters
With the use of the bifurcation management feature in MIKE HYDRO, the
computational engine will change the bifurcation parameter, in order to maximise the satisfaction of the highest global priority water user. Thus, in this
small example, the bifurcation will be set to 0.7 or 7 m3/s (and therefore 3
m3/s to the opposite sub-branch), setting the demand satisfaction of the water
user with GP 1 to 100 %, while the demand satisfaction of the water user 2
will be down to 3/5 (60 %).
Since the bifurcated flows in all bifurcation nodes are not a constraint in the
network, the bifurcated water could be re-assigned if needed. This means
that it can be assigned to a water user even, regardless of whether this water
user is located upstream or downstream to the bifurcation node.
This GPW source feature for managing reservoirs and bifurcations allows to
enforce the optimal value for the operations of these water sources in Mike
Hydro, making the optimal management of water resources and optimizing
water distribution among prioritized supply connections (water users).
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Global Ranking
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12
Sediment Transport
A simple sediment transport option is available in MIKE HYDRO Basin for
use in connection with Reservoir sedimentation simulations.
The Sediment transport page and the Reservoir sedimentation simulations
are enabled through activating the ‘Include reservoir sedimentation’ option in
the ‘Simulation specifications/modules’ page.
The overall approach for the sediment transport and reservoir sedimentation
feature is, that sediment is transported un-disturbed through the river network
and potentially deposited in Reservoirs.
The input required for the sediment transport calculations are sediment properties for the sediment fractions included. These definitions are made in the
Sediment properties dialogue.
Additionally, sediment loads must be defined. These are defined as time
series input through a combination of a Total sediment load time series and
sediment fraction percentage time series. Sediment load are defined as input
to Catchments and consequently, added as sediment load to the river at the
location of the specific Catchment node.
Sediment transport and Reservoir sedimentation approach
The reservoir sedimentation module is not a sediment transport model. Sediment is supplied by catchments and is routed through the river network under
the assumption that no erosion or deposition takes place in the rivers and
deposition of sediments will solely occur in the Reservoirs.
If a reservoir is filled with sediments or other conditions prevents inflowing
sediments to deposit in the specific Reservoir, sediment surplus will be transported further downstream in the system. The sediment is routed to the river
downstream of the reservoir and to users supplied by the Reservoir. Sediment is distributed between connected rivers and users according to the discharge distribution.
Reservoir sedimentation change the properties and storage capacity of the
reservoirs. The Level-Area-Volume (LAV) curve of each reservoir is continuously updated during a simulation based on the amount of sediment deposited in the reservoirs.
The frequency at which LAV is updated during simulation can be controlled
by the user. The update frequency is specified in the Time step control dialogue (cf. 4.4 Time Step Control (p. 53)).
If the bottom level of the Reservoir due to deposition reaches the dead zone
level, a warning will be issued, and no more sediment will be deposited in this
reservoir.
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Sediment Transport
12.1
Sediment Properties
If reservoir sedimentation is included in Basin Modules the following Sediment properties must be defined:

Density

Porosity

Settling velocities
Density is assumed equal for all sediment types. By default the model uses a
density of 2650 kg/m3, which is the density for quartz.
Porosity (the volume of pore-space in sediment) is assumed equal for all sediment types. By default the model uses a porosity of 0.4 which is the typical
porosity of naturally deposited, non-cohesive sediments.
The sediment can be defined by one or more grain size classes in the table.
Each grain size class must be assigned a settling velocity. To add a sediment
grain size class click the ‘+’ in the tool bar above the sediment class table and
specify the associated settling velocity.
Table 12.1 shows some average settling velocities for various grain sizes
.
Table 12.1
160
Sieved diameter ds, Spherical diameter dv, fall (or sedimentation) diameter df and associated settling velocities w in water with a temperature
of 10ºC and 20ºC.Source: Engelund & Hansen, 1972: ‘A monograph on
sediment transport in alluvial streams’
ds (mm)
dv (mm)
df (mm)
w (10ºC)
(m/sec)
w (20ºC)
(m/sec)
0.089
0.10
0.10
0.005
0.007
0.126
0.14
0.14
0.010
0.013
0.147
0.17
0.16
0.013
0.016
0.208
0.22
0.22
0.023
0.028
0.25
0.25
0.25
0.028
0.033
0.29
0.30
0.29
0.033
0.039
0.42
0.46
0.40
0.050
0.058
0.59
0.64
0.55
0.077
0.084
0.76
0.80
0.70
0.10
0.11
1.25
1.4
1.0
0.15
0.16
1.8
1.9
1.2
0.17
0.17
MIKE HYDRO - © DHI
Sediment Properties
Note that the sediment properties are global values used throughout the
entire model. It is not possible to make spatial variation of definitions for sediment fraction properties.
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Sediment Transport
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Notes on ECO Lab
13
Water Quality
MIKE HYDRO includes options for Water Quality (WQ) simulations. WQ-simulations in MIKE HYDRO utilises the ECO Lab framework and hence, offer a
versatile and extremely flexible options for WQ-modelling. Water Quality simulations can be performed using either standard, predefined ECO Lab templates or user-defined templates with tailored Water Quality models.
13.1
Notes on ECO Lab
ECO Lab is a numerical lab for Ecological Modelling. It is an open and
generic tool for customising Aquatic Ecosystem models to describe water
quality, eutrophication, heavy metals and ecology. The module is mostly used
for modelling water quality as part of an Environmental Impact Assessment
(EIA) of different human activities, but the tool is also applied in aquaculture
for e.g optimizing the production of fish, seagrasses and mussels. Another
use is in online forecasts of water quality.
The need for tailor-made ecosystem descriptions is big because ecosystems
vary. The strength of this tool is the easy modification and implementation of
mathematical descriptions of ecosystems into the hydrodynamic MIKE
engines.
ECO Lab utilises so-called Template files with the filename ‘.ECOLab’ (in the
following named ECO Lab File). The ECO Lab template files are customized
collections of equations and parameters required for a specific type of Water
Quality simulations. The user may use one of the predefined ECO Lab Templates, which is installed together with the MIKE Zero installation - or may
choose to develop own model concepts. The module can describe dissolved
substances, particulate matter of dead or living material, living biological
organisms and other components (all referred to as state variables in this
context).
The module was developed to describe chemical, biological, ecological processes and interactions between state variables, but it can also describe the
physical sedimentation process of components. State variables included in
ECO Lab can either be transported by advection-dispersion processes based
on hydrodynamics, or have a more fixed nature (e.g. rooted vegetation).
More details on ECO Lab can be found in the specific ECO Lab documentation, which in most installations will be located at ‘C:\Program Files
(x86)\DHI\2016\MIKE Zero\Manuals\MIKE_ZERO\ECOLab_OilSpill’.
13.2
Water quality definitions
Water Quality must be enabled by the user if it should be included in the simulation and in the MIKE HYDRO tree view. To activate Water Quality it is
163
Water Quality
required to enable the ‘Water quality’ checkboxes under Simulation specifications\Modules.
The Water quality definitions page includes the following tab-pages:

General

Locations and Parameters
General
Default Water Quality model
The current version support only running one water quality model (ECO Lab
template) at a time. The selected and active template is therefore always the
default water quality model - and this setting cannot be changed presently.
Solution method
Water quality calculation is based on predefined ECO Lab templates which
contains a model defined by a number of coupled differential equations,
which is solved through numerical integration and interactions between each
equation.
Solution method is a selection of the Integration Method for solving the coupled ordinary differential equations defined in the ECO Lab file. Three different built-in integration routines (solution methods) are available (please
consult the ECO Lab Reference Manual for details on the methods for solving
the coupled linear differential equations in the ECO Lab framework):



Euler: Euler or Linear Solution
A very simple numerical solution method for solving ordinary differential
equations.
RK4: Fourth order Runge-Kutta.
A classical numerical solution method for solving ordinary differential
equations. It has normally higher accuracy than the Euler method but
requires longer simulation times. The fourth order Runge Kutta method
requires four evaluations of equations per time step.
RKQC: Fifth order Runge-Kutta with Quality Control
A numerical solution method for solving ordinary differential equations.
The accuracy is evaluated and the time step is adjusted if results are not
accurate enough. The method requires 6 evaluations at each time step
to take a so-called Cash-Karp Runge Kutta step and the error is estimated as the difference between a Runge Kutta fourth order solution and
the Runge Kutta fifth order solution.
The accuracy (and the computing time) varies for the three integration routines.
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Water quality definitions
The most accurate result will be calculated when using RKQC. However, in
some cases the same results can be obtained - using less computational time
- with the less advanced options; RK4 or EULER.
In general, it is recommended to use the RKQC routine. RK4 ad EULER
methods are generally only applied during the set-up and initial calibration
phase of a project. If the RK4 or the EULER routines are used, it is strongly
recommended to run an additional simulation with the RKQC routine and
compare the two results (RKQC versus RK4/ EULER) before making any
conclusions based on the model.
In the case of a very dynamic model system with steep concentration gradients in one or more of the components, integration may not be possible when
using the RKQC routine, and an error message will appear. Reducing the
time step will help in most cases, but sometimes the gradients are so steep,
that they cannot be solved accurately. The Quality Control of RKQC ensures
that all components are calculated within an accuracy of 1 µg/l. Using the
second best routine (RK4), where no Quality Control is included, the steep
gradients can be solved in a relatively accurate way and RK4 is therefore recommended when integration is impossible with the RKQC routine.
Update frequency
The update frequency is a parameter that allows to define how often the
water quality processes will be calculated during the simulation. The update
frequency is defined as a multiplum of the simulation time step but currently it
is decided to keep the frequency equal to one in MIKE HYDRO Basin in order
to keep the water quality processes simulated on each Basin simulation time
step. ECO Lab template file
The WQ modelling is based on predefined ECO Lab templates (Water Quality
Models). Two predefined ECO Lab templates are included in the MIKE
HYDRO installation and they can be located in the folder: ‘C:\Program Files
(x86)\DHI\2016\MIKE Zero\Templates\ECOLab’.
Templates supplied with the MIKE HYDRO installation are:

‘MikeHydroWQ_DO.ecolab’

‘MikeHydroWQ_noDO.ecolab’
Predefined ECO Lab templates includes BOD, Dissolved oxygen (DO), NH4,
Nitrate (NO3), Phosphorus (Ptotal), bacteria E.Coli and a User-defined degradation component.
The difference between the two templates is that the former includes dissolved oxygen processes while the latter does not include dissolved oxygen
processes.
The State variable overview of a MIKE HYDRO ECO Lab template is presented in Figure 13.1.
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Water Quality
Figure 13.1
ECO Lab editor with overview of State Variables for the ECO Lab template: ‘MikeHydroWQ_DO.ecolab’
To add an ECO Lab template (Water Quality Model) click on the ‘Add’ button
at the right hand side of the Water Quality Models table and a new row will
appear in the table. Click on the row, then click on the ‘...’ button in the righthand corner of the row (or click on the ‘...’ button next to the ECO Lab template file cell) and open the appropriate ECO Lab template from the pop-up
window. The predefined default templates can be found in the installation
path under ‘MIKE Zero\Templates\ECOLab\’.
Once successfully loaded, all parameters (i.e constants, state variables,
derived variables and forcing) of the ECO Lab template and their properties
are automatically shown in the Variables overview table. The information in
this table cannot be edited.
Note: The current version allows only one ECO Lab template to be loaded.
Locations and Parameters
In the Locations and Parameters dialogue, the location and values of water
quality parameters may be specified. This includes both initial values and pollution loads from (point) sources.
Locations
Once an ECO Lab template has been loaded (see ECO Lab template file in
General (p. 164)) a ‘Global Parameter’ location is automatically added to the
list of locations. The parameters specified for the ‘Global Parameter’ location
(see Location sub type below) are used as default values for the WQ modelling.
Local WQ Parameter locations are included by clicking ‘Add from MIKE
HYDRO’. This opens a new dialogue window with all possible WQ parameter
location in the setup. This includes Branches, Water users (return flows),
Reservoirs and Catchments. Click ‘Select’ to add a location in the WQ model.
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Water quality definitions
Location sub type
Locations are defined by their type (i.e. Global, Branch, Water user, Catchment or Reservoir) and their ‘Location Sub Type’. The available ‘Location Sub
Types’ depends on the ‘Location Type’ but includes the following:

Initial

Source

Point Source

Groundwater (various types) - only available for catchments with groundwater
A Local WQ Parameter Location may be assigned several ‘Location Sub
Types’. This is done by adding the location from MIKE HYDRO as many
times as required.
Conservative transport
By default Conservative Transport is enabled, and the WQ parameters are
simply transported through the model setup (i.e. no processes alter the WQ
parameter concentrations). If Conservative Transport is disabled, various
decay processes will affect the WQ parameters. This is specified below as
Residence Time Calculation Type.
Residence time calculation type
Residence time intuitively determines the degree of solute decay. Mathematically, it is the upper integration limit of the first-order differential equations
shown in the ‘MIKE HYDRO Basin Water Quality Scientific Documentation’.
There are five different Residence Time Calculation types:


User defined Residence Time and Water Depth: Time series files must
be specified for Residence time (and Water depth if DO is included as a
parameter). Click on Residence/Water Depth file cell and click the
browse ‘...’ button to select the right time series file. This option is convenient if you do not have any other data that allow residence time to be
calculated. Water volume is calculated as the outflow rate times the residence time. If you model DO, you also need to specify water depth and
reach length.
User defined Water Depth: Time series files must be specified for Water
depth. Click on Water Depth file cell and click the browse ‘...’ button to
select the right time series file. With this option Reach length ‘l’ must be
specified in the Locations table (Length column) and Width ‘w’ must be
specified under Routing (see 6.5 Routing (p. 69)). Water volume V is calculated as follows V = w  l  h where h is water depth. Residence time
T is calculated as T = V  Q where Q is the reach outflowrate (by convention, it could also be argued that Q should be the average of inflow
and outflow rates, if those differ due to routing).
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Water Quality



Calculated Water Depth: To use this option, Water level calculation must
be specified under Routing (see 6.5 Routing (p. 69)). Calculation of volume and residence time is the same as above (User defined Water
Depth).
None No Decay: Conservative transport.
From Routing: To use this option, a Routing method must be selected
under Routing (see 6.5 Routing (p. 69)). The calculated reach storage S
allows residence time T to be found as T = S  Q . Reach length is not
required.
Parameters
To add parameters to a location, select the relevant location from the list and
click the ‘Add’ button in the upper right-hand corner of the dialogue window.
This opens a new dialogue with all available parameters. Select the required
parameters (our press Crtl-A - to select all). The selected parameters are
then associated with the location (and Location Sub Type) and the following
properties may be edited.
Note that depending on the chosen Location Sub Type, the values of the
state variables represent either ‘Initial’ values (used only during the initial
time-step) or ‘Load’ values applied at each time-step.
Parameter type
By clicking on the cell, the Parameter Type may be set to either ‘Constant’ or
‘Time Varying’.
Fixed value
If a ‘Constant’ Parameter Type has been selected, the value may be edited
here.
Data file
If a ‘Time Varying’ Parameter Type has been selected, a time series must be
specified by activating the Data File cell, clicking on the ‘...’ button in the right
hand side of the cell and select an existing Time series.
Factor
A factor may be multiplied to the value. This may be used to evaluate impacts
of reduced pollution loads or to represent related substances.
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Standard Results
14
Result Specifications
MIKE HYDRO simulations creates results from the selected type of model
executed. Results are saved in result files of a specific type depending on the
type of simulation.
The Results specifications dialogue enables the definition of location and
names of the result files created during the simulations.
MIKE HYDRO suggests a default location and file names for simulation
results, and it is therefore not strictly required to edit the result specifications
by the user prior to running a simulation.
However, the Results specifications dialogue also enables the user to define
a user-specified location as well as file names for results produced from the
MIKE HYDRO simulation.
14.1
Standard Results
Simulation Results are stored in result files and the location as well as file
names may be defined either using default definitions from MIKE HYDRO or
using user defined folders and file names.
Overall, three settings can be made:

Definition of Result folder path

Definition of Result file names
Details on result folder path specification
The ‘Use default result folder’ checkbox will determine whether you will use
the default defined result folder path or wish to define a result folder path
manually.
The default suggested result folder path will appear only after the MIKE
HYDRO file has been saved initially. Default folder path is then created as a
sub-folder to the folder where the .mhydro file is located. The name of the
sub-folder will be a mix of the mhydro file folder name and path as indicated
in the following example.
Example: A MIKE HYDRO setup file with the name ‘WB-sc1.mhydro’ has
been saved to the location; ‘C:\projects\WB-CC\Models’. In this case, the proposed default folder will be:
‘C:\projects\WB-CC\Models\WB-sc1.mhydro - Result Files’
To make a user-defined file path definition it is required to deactivate the
checkbox and then use the
button to browse for required folder. Press
‘OK’ when the correct folder has been located and result files will then be
saved to this specific folder during simulation.
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Result Specifications
Details on result file name specifications
The ‘Use default names’ checkbox defines whether the default proposed file
names or user-defined file names for results are used.
The default proposed result file name is created from the user-specified string
in the ‘Title’ text-field in the ‘Simulation specifications -> Description’ page of
the tree view, and the default result file name can hence be adjusted by editing the ‘Title’ definition of the project file.
Additionally, the specific type of simulation is included in the default file name
to distinguish between multiple result files created in one simulation (see
example below)
Example: The user has defined the following ‘Title’ in the mhydro file: ‘CC
scenario 1-A’. This will result in the following default result file names:
Basin module result file names:
–
–
–
Basin results: ‘RiverBasin_CC scenario 1-A.dfs0’
Rainfall-Runoff results: ‘RainfallRunoff_CC sceario 1-A.dfs0’
Result file-types for the MIKE HYDRO modules is:

Basin module: ‘.dfs0’
Note that simulation results with a title already used will overwrite the existing
results unless a new result folder/file has been specified.
To make a user-defined result file name definition, simply deactivate the
checkbox specify the requested result file name in the file name edit field.
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File: Import and Export of MIKE HYDRO data
15
Main menu bar features
There are a number of effective features and tools to assist in model creation
which are accessible from options within the Main menu bar.
Specific main menu bar features described in this section include:
15.1

File menu: Import and Export of MIKE HYDRO model data

Tools menu: Cross sections processing tools and Load calculator
File: Import and Export of MIKE HYDRO data
MIKE HYDRO includes import and export features for model data components. The import and export option is activated from the main menu bar
selecting either Import or Export from the File menu.
15.1.1 Import
Import from Shapefile
MIKE HYDRO include a comprehensive shapefile conversion feature, enabling import of most georeferenced model objects stored in Shapefiles in to a
MIKE HYDRO model.
It is possible to import and define River branches, Water users, Reservoirs,
Hydropower features as well as Catchment and Rainfall Runoff method from
Shapefiles for the Basin module.
Figure 15.1 presents the dialogue for import of Basin model data from Shapefiles.
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Main menu bar features
Figure 15.1
Import of Basin model features from Shapefile
To import model features from shapefile, do the following:
1.
Activate the checkmark in front of the model features that should be
imported (multiple features can be imported in one operation).
2.
Browse and select the specific shape file using the file selection button
'…'.
3.
Define feature specific attributes from the shape file using the dropdown
menus. Each dropdown menu will present the shape file attributes that
are possible to use for the specific MIKE HYDRO feature parameter.
Note: It is not required to specify all attributes in drop down menus. If
some are left blank, the import utility will just assign default values for
these features.
Some attributes in the shape files must be assigned specific numerical values
to be recognized and imported correctly by MIKE HYDRO, as some of the
features in MIKE HYDRO are defined by a numerical value rather than a
string. The table below presents the attribute values for specific feature type
definitions used during import from shapefile to MIKE HYDRO.
Table 15.1
172
Attribute values for specific feature type definitions
Feature attributes
Options
Values
Water User Type
Regular User
Irrigation User
0
1
Reservoir Type
Rule Curve Reservoir
Allocatio nPool Reservoir
Lake
0
1
2
MIKE HYDRO - © DHI
File: Import and Export of MIKE HYDRO data
Table 15.1
Attribute values for specific feature type definitions
Feature attributes
Options
Values
Use Polyl. Area
True
False
1
0
RR method
(Rainfall Runoff Model Type)
None
NAM
UHM
Time Area
Kinematic Wave
0
1
2
3
4
When selections and filename specifications are complete, press the 'Run'
button to execute the import of model data from shapefiles. Press 'Close' to
stop the conversion or to close the dialogue.
Note: Reservoirs are attached to river branches in MIKE HYDRO, but
imported points (for reservoirs) must not necessarily be strictly superimposed
to the imported branches. These objects will be inserted on the closest location on the river branch they belong to. Additionally, their chainages will be
automatically computed based on this location.
Import from MIKE 11
The Import from MIKE 11 option enable import of River model data from
DHI’s River modelling package; MIKE 11 in to the River module of MIKE
HYDRO.
More details on the MIKE 11 Import can be found in MIKE HYDRO River documentation.
Import from ISIS
Import from ISIS option concern River modelling and conversion of River
model data in to the River module of MIKE HYDRO.
More details on the MIKE 11 Import can be found in MIKE HYDRO River documentation.
15.1.2 Export
Export to Shapefile
The majority of georeferenced model features defined in MIKE HYDRO Basin
can be exported to Shapefiles.
The export option is activated through ‘Export to Shape files', which opens
the dialogue as presented in Figure 15.2.
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Main menu bar features
Figure 15.2
Export MIKE HYDRO Data to Shapefile dialogue
The dialogue contains two groups of data; 'Common features' which are features that are also used by other modules than Basin, and 'Basin Module
Features' which are module specific features used only in the specific MIKE
HYDRO module.
Export the requested model data by activating the checkbox in front features
that should be processed and specify a shapefile names for the individual
features. Use the file selection button '…' for specifying the output shapefile
names.
After completing selections and filename specifications, press the 'Run' button to execute the export of model data to shapefiles. Press 'Close' to stop
the conversion or to close the dialogue.
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File: Import and Export of MIKE HYDRO data
Shapefile content from Export of MIKE HYDRO features will include the following information:
Table 15.2
Export from MIKE HYDRO; Shapefile content
MIKE HYDRO
features
Shape type
Key variables to export as
shapefile attributes
Attribute name
Attribute type
Branches
River shapes
(Polylines)
Branch name
Identifier
Topo-ID
Start Chainage
End Chainage
Flow direction
Branch Type
BR_BrName
BR_ID
BR_TopoID
BR_StartCh
BR_EndCh
BR_FlowDir
BR_Type
Text
Text
Text
Double
Double
Short integer
Short integer
Branch
connections
Connecting lines
(Polyline)
Branch name
Upstr. Type
Upstr. Branch name
Upstr. Chainage
Upstr. Storage ID
Downstr. Type
Downstr Branch name
Downstr. Chainage
Downstr. Storage ID
BC_BrName
BC_UpsType
BC_UpsName
BC_UpsCh
BC_UpsStID
BC_DwsType
BC_DwsName
BC_DwsCh
BC_DwsStID
Text
Short integer
Text
Double
Text
Short integer
Text
Double
Text
User defined
chainages
Points
Branch name
Chainage
UDC_BrName
UDC_Ch
Text
Double
Catchments
Catchment
shapes
(polygons)
Name
Use Polygon Area
Catchment Area
Rainfall-Runoff model
Branch
Chainage
Cat_Name
Cat_AreSel
Cat_Area
Cat_RRMod
Cat_BrName
Cat_Ch
Text
Short integer
Double
Short integer
Text
Double
Catchment
connections
Connection
(Polyline)
Catchment name
Branch name
Chainage
Upstream Ch
Downstream ch
CC_CatName
CC_BrName
CC_Ch
CC_UpsCh
CC_DwsCh
Text
Text
Double
Double
Double
River Nodes
Node locations
(Points)
Branch name
Chainage
Identifier
Type
RN_BrName
RN_Ch
RN_ID
RN_Type
Text
Double
Text
Short integer
Water Users
User Locations
(Points)
Name
Type
WU_Name
WU_Type
Text
Short integer
Water User
Connections
Polyline
Water user name
Identifier
Supply Branch name
Supply Chainage
Supply priority
Return Branch name
Return Chainage
WUC_Name
WUC_ID
WC_SuppName
WC_SuppCh
WC_Priorit
WC_RetName
WC_RetCh
Text
Text
Text
Double
Long integer
Text
Double
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Main menu bar features
Table 15.2
Export from MIKE HYDRO; Shapefile content
MIKE HYDRO
features
Shape type
Key variables to export as
shapefile attributes
Attribute name
Attribute type
Reservoirs
Reservoir
locations
(Points)
Name
Identifier
Branch name
Chainage
Type
RES_ResName
RES_ID
RES_BrName
RES_Ch
RES_Type
Text
Text
Text
Double
Short integer
Hydro power
Hydro power
locations
(Points)
Name
Identifier
Reservoir
Branch name
Chainage
HP_HPName
HP_ID
HP_Reserv
HP_BrName
HP_Ch
Text
Text
Text
Text
Double
Export to MIKE 11
The Export to MIKE 11 option target the River module of MIKE HYDRO allowing to create MIKE 11 river models from MIKE HYDRO River.
More details on the Export to MIKE 11 option can be found in MIKE HYDRO
River documentation.
Figure 15.3
Export Preprocessed DEM to dfs2
If Digital Elevation Model (DEM) is included in MIKE HYDRO for use in
catchment and river delineation it is requirement to make a preprocessing of
the DEM prior to these operations. This export function enable an option for
saving the preprocessed data from this process in to a dfs2 file for general
information about the preprocessing results.
15.2
Tools
The ‘Tools’ menu in the MIKE Zero menu bar contains a set of tools used to
help creating and modifying the setup.
The following tools are available:

176
Tools: Load Calculator
Calculate pollutants flux to the river from different pollutant sources.
MIKE HYDRO - © DHI
Tools
15.2.1Tools: Load Calculator
The Load calculator is a tool to determine the amount of pollutants that are
absorbed by the water in its path through catchments and groundwater areas
towards the river network. The pollutants are computed considering different
pollutant sources related to farming, agriculture, or industrial activities, including animal or human waste, sewage sources, or use of fertiliser, etc. The
input consists of the pollutant sources and amounts, and the output consists
on the actual flux of pollutants that makes it into the river network.
The tool can be applied as a stand-alone tool for calculating average mass
fluxes of pollutants for individual sub-catchments (e.g. kg/catchment/year) or
on a raster grid basis (e.g. kg/grid/year). Alternatively, it can be used to provide the pollution loading for a MIKE HYDRO Water Quality model. Pollution
loads may include both point and non-point sources.
All loads are initially calculated as constant mass fluxes for each sub-catchment, e.g. kg/year, however when applying the Load Calculator together with
e.g. the MIKE HYDRO Water Quality model there are several ways to translate the constant mass fluxes into mass flux time series depending on e.g.
runoff time series or any other known temporal variations.
Distance specific decay or retention of pollutants can be included taking into
account the distance between the location of the pollution sources and the
presumed outlet in the river network.
The Load Calculator dialogue consists of four main tabs that will hold the
required information for the engine to construct the loads:

Sources - for specifying pollution sources,

Catchments - for specifying the transport,

Decay - for specifying the retention of pollutants, and

Output - for specifying how the output is to be stored.
Sources
The sources tab is used to define the various sources that are to be modelled
in the setup. The individual sources are inserted by clicking the ‘Add’ button.
The user will then have to enter the name of the source e.g. ‘manure’.
This will generate a new sub tab within the main source tab. The dialogue
may hold multiple sources, each added or removed using the buttons at the
lower right corner of the main tab. Each source must be defined using the
associated dialogue.
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Main menu bar features
Definition layer
Shape file
Click the browse ‘...’ button to browse for and select a shape file that includes
information about the source, e.g. data on fertiliser application, population
numbers, etc. The shape file may either be a point or a polygon file. The text
field cannot be edited but will be populated with the path to the shape file. The
shape file is used to define the source and the following two attributes must
be defined using the drop-down menues:


Name Field: Select a field in the attribute table of the layer that includes
a unique ID or Name of the administrative or statistical unit.
Value field: Select a field in the attribute table of the layer that includes
data of the fertiliser application, head count, release amount, etc.
Category
This field allows an implicit aggregation of point sources. It defines sub sets of
the total loads, in such a way that the contribution of each category can be
disaggregated from the total, in order to have an overview of the relative contribution of each category in relationship with the total load.
Components
Select the components that are to be transported in the system. The combobox is populated through querying the ECO Lab template in the setup of the
constituents available (see section 13 Water Quality (p. 163)).
Note that only ‘State variables’ where ‘Transport = ADVECTION_DISPERSION’ will be shown and handled in the Load Calculator.
Time distribution
The user may select to modulate the load with the runoff. This is done by enabling ‘Distribute according to runoff’. The runoff time series is applied as a
temporal multiplication factor to distribute the mass fluxes of the pollution
source in time for the current load source. Time distribution of components
can be defined individually using an alpha series stored in a dfs0 file.
Modification factors
The table is populated by the user inserting a line. The districts are selected
from a combobox based on the IDs in the shape file. The columns are added
based on the components selected above. Modifications factors not supplied
are equal to unity (n=1).
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Tools
Catchments
The catchment tab holds information specific to the catchments. It consists of
two main group boxes. The top one holding information concerning runoff
hydrographs the lower focusing on the concentrations of the baseflow in the
catchments.
Click ‘Load all catchments’ to load the existing catchments in the setup. For
updating existing catchments click ‘Update all catchments’, this will add missing catchments to your tables.
Catchment runoff
This box is holding information concerning runoff hydrographs. For non-point
sources, pollutant transport to the river (as a flux) is typically positively correlated with the Rainfall runoff. Non-point sources include all sources specified
as Livestock or Fertiliser source types. To account for this runoff dependent
flux of non-point pollutants, it is assumed that pollutant concentrations in the
runoff are constant.
The Runoff Start and End times are applied to specify a period for which
annual non-point loads (e.g. kg/year) are translated into an average pollutant
concentration (e.g. mg/l). The total annual load (i.e. total mass) is divided by
the total accumulated runoff (i.e. total volume) for the specified period to calculate the mean runoff concentration (e.g. in mg/l) of each pollutant originating from non-point sources. To provide a variable load flux input time series,
this concentration is then multiplied by the runoff time series specified for
each Catchment in the setup.
Typically, the period specified will be of one year duration and represent the
calibration period for a MIKE HYDRO Water Quality model.
If the assumption of a constant concentration of a pollutant in the runoff originating from non-point sources is not satisfactory, it is possible to apply an
alpha time series to distribute the non-point sources in time.
Catchment baseflow concentrations
The table holds the baseflow concentration values of the constituents for
each catchment. The columns are added based on the selected components
(see section Sources (p. 177)).
This option is only relevant if a groundwater runoff component has been
explicitly included in the setup. This must be included as separate time series
files, either as a user specified time series or as a NAM model simulation
result. When a groundwater component is included, only the fraction of the
total load corresponding to:
(Total Runoff - Groundwater runoff)/Total Runoff
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Main menu bar features
will be added to the catchment node in the river network. The rest of the loads
are ignored. Instead a user specified baseflow concentration must be specified for each pollutant component representing the expected pollutant concentration in the groundwater discharging into the river section. Baseflow
concentrations can be identified from water quality measurements as concentrations found during low flow situations in parts of the river where domestic
and point sources are absent. Thus, the baseflow concentration is often a
calibration parameter.
This approach has been introduced based on the assumption that most nonpoint loads are derived from the overland or drainage flow components of the
hydrological cycle. This is often seen in rivers dominated by non-point
sources resulting in a high concentration of pollutants during high flow and
low concentrations during low flow. The fluctuation of concentrations in this
case is typically determined by the relation between groundwater and surface/drainage water discharge to the river. Baseflow concentrations are typically considerably lower (e.g. <10%) compared to surface/drainage flow.
In some cases, though, transport through groundwater may be significant. In
those situations it may be recommended not to include groundwater separately as described above. Instead use the Distance decay function to
describe the overall retention of pollutants in the total runoff not distinguishing
between different types of runoff components.
Decay
The decay tab is only active if ‘Apply Distance Decay’ has been enabled. This
is then applied globally to all catchments.
A river network shape file is used to calculate the distance to the nearest river
network point. Please note that the shape file may use a finer resolution than
the one used for the modelling of water movement in the rivers.
A fixed temperature is used throughout the model.
Output
The Output tab holds the information on the output type along with the mechanism for launching the load calculation.
A switch ‘Basin’ controlling whether the output should be saved as Basin data
or not.
Statistics in the form of a shape file with attributes describing the statistics will
be produced if the switch ‘Maps and Statistics’ is checked.
Calculation process is started with ‘Generate loads’ button and a progress
bar is updated based on the number of catchments handled.
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APPENDICES
181
182
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APPENDIX A
183
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A.1
The Linear Reservoir Model
In a linear reservoir model, groundwater discharge, i.e., flux through the outlet(s) is proportional to the water level, and because catchment area is constant, it is also proportional to the storage. Specifically, the coupled differential
equations solved are:
h 1
-------- =  – k 1 – k 1   h 1 – L 1  + q rech arg e + q stream_seepage
t
(A.1.1)
h 2
-------- = k i  h 1 – L 1  – k 2  h 2 – L 2  – q pumping
t
(A.1.2)
where the variables related to the geometry (h and L) and time constants k
are defined in Fig A.1.1. The dimensions of L and h are [Length].
Fig A.1.1
The geometry of the linear reservoir model
The mathematical solution of the linear reservoir equations in MIKE HYDRO
is also valid for situations where the groundwater storage is emptied (when
outflows permanently exceed inflows), or when overflow occurs (when inflows
permanently exceed outflows). This is also valid when the deep groundwater
level reaches the shallow outlet, causing flow back into the shallow reservoir.
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The Linear Reservoir Model
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A.2
Hydropower - Formula
MIKE HYDRO calculates the hydroelectric power produced from the following
formula:
P = h  Q   Q    h   g   water
(A.2.1)
Where P is the power generated, h is the effective head (difference) [L], Q
is the discharge/release through turbine(s) [L3/T],  is the machine (power)
efficiency [-], g is the gravitational constant [L/T2] and  water is the density of
water [M/L3]. Machine (power) efficiency  may also be specified as a function of Q, in which case   h  is replaced by   Q  in equation (A.2.1).
The effective head difference is:
h  Q  = h reservoir – h tailwater  Q  – h conveyance  Q 
(A.2.2)
The hydropower formula is non-linear because of the dependencies of head
difference on discharge and machine efficiency. Tailwater levels are generally
a function of discharge, and so are additional conveyance head losses in the
channel (both increase with discharge). In addition the tailwater can also
become governed by backwater from the reservoir downstream rather than
discharge of the supplying reservoir. In the simulations, the applicable tailwater level for use in equation (A.2.2) is found from
h tailwater = max  h tailwater   Q  h downstream_reservoir 
(A.2.3)
In MIKE HYDRO, the following inter-dependencies between variables can be
assumed constant or insignificant by leaving out the respective detailed specifications:
h tailwater  Q  = h reservoir_bottom_level (leaving out the tail water table)
h conveyance = 0 (leaving out the conveyance head loss table)
  h  = 0.86 (leaving out the power efficiency table)
Water demand for power generation is calculated by solving the power formula, equation (A.2.1), for Q (the solution must be found iteratively). When
the effective head difference is small, turbines are however shut off, both
because they are inefficient and because the required discharge would grows
very large. Accordingly, a minimum head for operation can also be specified.
If the head is less than the minimum head, Q is set to zero, i.e., no water is
routed through the turbines, regardless of demand.
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Hydropower - Formula
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Climate Models
A.3
Irrigation
A.3.1 Climate Models
The climate module accepts a number of commonly available climate inputs
and converts them into precipitation and the input required by the reference
ET model, according to the selected Climate model. Two model types are
currently available:


The Rainfall only model. This is the simplest climate model, only requiring a Rainfall time series as input.
The FAO 56 climate model. This model is only relevant if the evapotranspiration model is of the type FAO 56. The required inputs for this model
are climatic data, rainfall data and geographical information about the
location of the irrigated area
A.3.2 Reference ET Time Series Calculation
The reference ET model is responsible for providing the Crops module with
reference evapotranspiration in each time step of the simulation. The evapotranspiration rates may either be calculated based on the input from the Climate model, or provided directly as a time series.
Two types of the reference ET models are currently available:

Reference ET time series

FAO 56 reference ET
A.3.2.1 Reference ET time series
As an alternative to the FAO 56 calculation of reference ET, this model type
accepts time series of reference evapotranspiration. This method works with
fewer data and must be used with the Rainfall only climate model type.
A.3.2.2 FAO 56 reference ET
The FAO 56 reference ET model is applied by default when selecting the
FAO 56 climate model. The FAO 56 reference ET model uses the standardised Penman-Monteith equation for calculating reference evapotranspiration
and it requires no additional input.
189
Irrigation
The reference ET is calculated as:
900
0.408  R n – G  +  ------------------- u 2  e s – e a 
T + 273
ET 0 = ------------------------------------------------------------------------------------------------ +   1 + 0.34u 2 
(A.3.1)
Where:
ET0: Reference evapotranspiration [mm day-1],
Rn: Net radiation at the crop surface [MJ m-2 day-1],
G: Soil heat flux density [MJ m-2 day-1],
T: Air temperature at 2 m height [°C],
u2: Wind speed at 2 m height [m s-1],
es: Saturation vapour pressure [kPa],
ea: Actual vapour pressure [kPa],
es-ea: Saturation vapour pressure deficit [kPa],
 Slope vapour pressure curve [kPa °C-1],
 Psychrometric constant [kPa °C-1].
The FAO Penman-Monteith equation provides the evapotranspiration from a
hypothetical grass reference surface and provides a standard to which evapotranspiration in different periods of the year or in other regions can be compared and to which the evapotranspiration from other crops can be related.
A detailed description of the calculation procedure for the Penman-Monteith
formulation is described in FAO 56, and contains the following calculation
steps:


190
Derivation of all required climatic parameters from the daily maximum
(Tmax) and minimum (Tmin) air temperature, altitude (z), mean wind speed
(u2) and geographical location.
Calculation of the vapour pressure deficit (es - ea). The saturation vapour
pressure (es) is derived from the mean temperature, which is assumed
to be the average of Tmax and Tmin. The actual vapour pressure (ea) is be
derived from the minimum temperature, which is assumed to equal the
dew-point temperature.
MIKE HYDRO - © DHI
Crops

Determination of the net radiation (Rn) as the difference between the net
short-wave radiation (Rns) and the net long-wave radiation (Rnl). These
variables are derived from geographical location, sunshine hours and
vapour pressure. The effect of soil heat flux (G) is ignored for time steps
smaller than 10 days as the magnitude of the flux in this case is relatively
small and ET0 is obtained by combining the results of the previous steps.
A.3.3 Crops
FAO 33 Yield Model
Attaching a yield model to a crop model allows the conversion of soil water
stress into the corresponding yield loss, and hence, to quantify the costs of a
soil moisture deficit. The yield model currently available is the FAO 33 Yield
Model.
This model is based on a so-called potential yield (Yp), which is the crop yield
under optimal conditions (no soil moisture stress). The sensitivity of a crop to
soil moisture stress depends on the growth stage. A crop will usually be more
sensitive to soil moisture stress in early growth stages than in late stages.
This is taken into account with a yield response factor (Ky). A yield response
factor has to be specified for each of four growth stages. Each stage is
assigned a length that may, but does not have to, be the same as the growth
stages in the Crops model to which it is related.
The crop yield is calculated as:
Ya
------ =
Yp
i=G

i=1
Et
1 – K yi  1 – -------a-

Et p
(A.3.2)
Where:
Ya: Actual yield [kg/ha]
Yp: Potential yield [kg/ha]
Eta: Actual transpiration [mm/day]
Etp: Potential transpiration [mm/day]
Index i is the i’th growth stage in a growing season with a total of G growth
periods.
A.3.4 Soil Model
The Soil model, also referred to as soil water model, keeps track of the water
flow between different layers in the soil profile and the time-varying water
content in each layer (see Fig A.3.2). The main task of the soil water model is
191
Irrigation
to keep track of the amount of soil water available for soil evaporation and
crop transpiration at any time during the simulation. The soil water content
may also be used by the irrigation module to determine the irrigation demand.
Fig A.3.2
Schematisation of the Soil Water Models. Each model uses a different number of layers
You can chose between three Soil model types:

FAO 56

ZIMsched

ZIMsched for Rice field
A.3.4.1 FAO 56
The FAO 56 Soil water model is a simple water balance based model that follows the recommendations provided in FAO 56 /3/ for use with the dual crop
coefficient method. More details are given in the following sections:
192

FAO 56 Soil model properties

FAO 56 Soil model computations
MIKE HYDRO - © DHI
Soil Model
FAO 56 Soil model properties
The following parameters need to be specified for the FAO 56 Soil water
model (see also Table A.3.1 for suggested representative values):
In the Soil moisture content dialogue:





Initial. This is the starting soil moisture content at the beginning of the
crop season [0-1]. The Initial soil moisture content is set for the Top soil
and the Root zone. For the Lower zone the initial soil moisture is by
default, at Field capacity.
Field capacity. This is the maximum water content held by the soil
against gravity [0-1]. Water cannot be retained in the top soil and the root
zone layer when the water is above field capacity, as it will drain away
under gravity. Soil moisture below field capacity is available for evapotranspiration until the soil moisture reaches wilting point.
Wilting point. This is the lowest soil moisture content at which plants
can draw water from the top soil and the root zone layers [0-1].
Porosity. This is the maximum soil moisture content that the soil can
contain [0-1].
Depth of evaporable layer. This is the depth of the top soil layer Ze
from which evaporation occurs [m].
Example: The amount of water in a soil column depends on the soil moisture
content and the length of the soil column. If the field capacity is 0.15, the wilting point is 0.05, and the length of the root zone is 0.5 meter, then the available amount of water for transpiration is: 500 mm.
Table A.3.1
The representative soil property values and maximum depletion by
evaporation for an evaporation layer of 0.1 m
Soil type
Field capacity Wilting point
Difference
Max.
depletion by
evaporation
[mm]
Sand
0.07-0.17
0.02-0.07
0.05-0.11
6-12
Loamy sand
0.11-0.19
0.03-0.10
0.06-0.12
9-14
Sandy loam
0.18-0.28
0.06-0.16
0.11-0.15
15-20
Loam
0.20-0.30
0.07-0.17
0.13-0.18
16-22
Silt loam
0.22-0.36
0.09-0.21
0.13-0.19
18-25
Silt
0.28-0.36
0.12-0.22
0.16-0.20
22-26
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Irrigation
Table A.3.1
The representative soil property values and maximum depletion by
evaporation for an evaporation layer of 0.1 m
Soil type
Field capacity Wilting point
Difference
Max.
depletion by
evaporation
[mm]
Silt clay loam
0.30-0.37
0.17-0.24
0.13-0.18
22-27
Silt clay
0.30-0.42
0.17-0.29
0.13-0.19
22-28
Clay
0.32-0.40
0.20-0.24
0.12-0.20
22-29
FAO 56 Soil model computations
The model keeps track of the soil moisture content in two soil water compartments:


The top soil layer from which only soil evaporation is drawn. The length
of this layer is specified as the "Depth of evaporable layer" and is
denoted Ze.
The root zone layer. The length of this layer corresponds to the actual
root depth (Zroot(t)), which can vary in time depending on the crop development. Transpiration takes place from this layer.
The wetting fraction (equals 1.0 for rain and specified by the user for irrigation) is taken into account when the exchange between the evaporable layer
and the root zone is calculated. For rain (wetting fraction 1.0) the sub model
assumes that the evaporable layer drains to the root zone as soon as the
water content has reached field capacity (above which free drainage can
occur). For wetting fractions less than 1, water will start draining at average
water contents lower than field capacity. (see Wetting fraction time series)

Water balance for the top soil layer. The water balance, per unit time,
is calculated in the following three steps:
–
Infiltration of rain and irrigation water (calculated in two steps).
First rainfall is added, and if storage is still available, irrigation is
added:
Infiltration = min   sat – old   Ze  1000 P 
Infiltration = min   sat –    Ze  1000  Wf Irr 
Where:
sat : Soil moisture content at saturation [-]
old : Soil moisture content to the old time [-]
 : Soil moisture in the top soil layer after rain is applied [-]
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Soil Model
P: Net rainfall after runoff [mm]
Irr: Irrigation demand [mm]
Ze: Depth of the top soil layer [m]
Wf: Wetting fraction [-]
–
Percolation to the root zone: After water from rain and irrigation
has been applied, the amount of water above field capacity percolates to the root zone layer assuming that water is instantaneously
drained, by gravity, out of the top soil layer.
Perc =   – fc   Ze  1000
Where:
 : Updated water content after irrigation has been applied [-]
fc : Soil moisture content at field capacity [-]
–
Updating the water content: The water content is now updated taking into account the evaporation from the top soil layer. Notice that
the water content in the top soil during periods with high infiltration
will be equal to field capacity minus the evaporation.
new  Ze  1000 = old  Ze  1000 – Ev + Infiltration – Perc
Where:
new : Final soil moisture content in the top soil at the new time [-]
Ev: Evaporation [mm]

Water balance for the root zone layer.The water balance, per unit time,
is calculated in the following two steps:
–
Root zone percolation. The percolation out of the root zone layer is
assumed to take place, by free drainage, instantaneously as soon
as the soil moisture content is above field capacity. It is calculated
from the following equation:
PercR =   – fc   Zroot  1000
Where Zroot is the thickness of the root zone. Zroot is time varying
depending on the crop stage.  is the intermediate soil moisture
content in the root zone layer after it has been updated with the percolation from the top soil layer.
195
Irrigation
–
Updating the water content. The new water content after the time
step is then calculated by:
new  Zroot  1000 = old  Zroot  1000 – Et – PercR + Perc
Where Et is the transpiration [mm].
A.3.4.2 ZIMsched
ZIMshed properties
The parameters for the ZIMsched soil water model are the same as those of
the FAO 56 model. Additionally, two extra parameters need to be specified:


Sat. hydraulic conductivity. The saturated hydraulic conductivity is also
called the saturated drainage coefficient [mm/h]. Since it is known that
the drainage of water from an unsaturated zone diminishes with diminishing soil moisture, water may not drain instantaneously from the time
when the water is above field capacity. In such cases water will be available for transpiration for a short period depending on the magnitude of
the saturated drainage coefficient.
Depth to groundwater. The unsaturated soil zone extends from the
ground surface to the groundwater table [m]. Based on the depth of the
top soil and the root zone layers, the lower soil layer can be calculated.
From this zone deep percolation to the groundwater takes place using
the same drainage formula as for the root zone layer.
ZIMsched Soil model computations
The ZIMsched soil water model is one step more complex than the FAO 56
soil model and simulates the water balance in the unsaturated soil column in
three compartments. The first two are identical to the ones presented in the
FAO 56 soil model. The third layer is denoted as:

The lower zone layer. It covers the soil column from the root zone to the
groundwater table. If the depth to the groundwater table below ground
surface is called Zgwt, the thickness of this layer is time varying equal to:
Zlower(t) = Zgwt - Zroot(t) - Ze.
Fig A.3.2 shows the schematic presentation on the soil column and the flows
involved.
In the ZIMsched model, the root zone percolation also only occurs when the
water content is above field capacity, and but the percolation is not instanta-
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Soil Model
neous and is soil-dependent, described by the saturated drainage coefficient
of the soil:
  – fc 
RootZonePercolation = --------------------------------  Ks
 por – fc 
(A.3.3)
Where Ks is the saturated drainage coefficient [m/s].
The updating of the soil moisture content in the root zone is calculated by:
new  Zroot  1000 = old  Zroot  1000 – Et – PercR + Perc
(A.3.4)
The deep percolation PercD from the lower soil layer is calculated by a similar equation as for the root zone percolation, and the new soil moisture content in the lower zone is calculated by:
new  Zlower  1000 = old  Zlower  1000 + PercR – PercD
(A.3.5)
ZIMsched for Rice field
The ZIMsched for Rice, a soil water model for rice crops, is an extension of
the ZIMsched model with an additional storage on the ground surface. This
allows water to be stored on the ground surface during growth of rice. The
model requires an extra parameter describing the maximum water depth that
can be stored on the ground (often called detention storage):

Max water depth. The maximum water depth [m] specifies the maximum water depth that can be held back on the ground surface before
surface runoff takes place. From this storage water can evaporate and
infiltrate into the top soil storage.
ZIMsched for Rice field computations
In the computations of the soil model for rice crops the actual water depth is
added to rain (not to the irrigation because the wetting factor would be
applied) and at the end of the calculation any excess of water on the top soil
is considered as ponded water (up to the maximum water depth). The
exchange of flow between different soil layers is identical to the ZIMsched
model.
As in ZIMsched model, first Top soil layer is filled, then the Root zone layer
and finally the lower zone. If there is an excess of water in the lower compartment (above field capacity), deep percolation occurs. At the end of the calculations, the excess of ponded water may generate runoff.
At the beginning of nursery stage (until start of land preparation) only a fraction of the field is used. The fraction, called Nursery area is specified in the
Crops module.
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Irrigation
A.3.5 Runoff Model
When it rains on the ground surface, a certain amount of the water may run
off, either as surface flow or as subsurface flow or both. The irrigation module
of MIKE HYDRO is considering a vertical water balance model for the soil
column from the ground surface to the groundwater table. The horizontal
extent of this soil column represents the field in which a certain crop
sequence is grown.
The total runoff from an irrigation field can be divided into two components, a
surface water runoff and a groundwater runoff. The latter is the amount of
water, which escapes the root zone and percolates to the groundwater storage. The percolation to groundwater is calculated whether a surface runoff
model is included or not, see further details in the Soil model section (wherever the link between irrigation node and catchment groundwater is
described).
The task of the runoff model is to calculate the surface flow part of the total
runoff. Surface runoff may occur either when it rains, when the crop is overirrigated, or when a combination of both happens.
A.3.5.1 Using the Runoff model or not
The surface runoff models are based on the assumption that when the soil is
wet, the infiltration capacity is small and a larger portion of rain will immediately run off as surface flow. This direct surface flow runoff can either be calculated as a function of the storage in the soil (and rice ponds) or as a
function of the actual rainfall.
When the runoff model option is selected, an “a priori” direct surface flow runoff is calculated and subtracted from the rainfall. The remaining rainfall (called
the net rainfall, PN) is input to the soil column water balance.
If PN together with the applied irrigation cannot be stored in the soil (or on the
ground surface, in case of rice fields), additional surface flow runoff may
occur.
If the irrigation node is connected to the river network, the calculated surface
runoff will return through the return flow channel to the river. If the irrigation
node is not connected to a river with a return flow channel, the water will be
lost from the model.
Note: The return flow fraction should normally be set to 1 for irrigation nodes,
as it does not reflect the fraction of water supplied to the node as for normal
water user nodes, but the fraction of calculated surface runoff.
However, if it is set to less than 1, it indicates that some surface runoff may be
lost on its way to the river. This effect could be described more correctly by
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Runoff Model
specifying a percolation loss in the return flow channel, because it would
enter the groundwater reservoir.
When the runoff model option is not selected, the total rainfall enters the soil
column water balance. If the rainfall and/or the irrigation input cannot be
stored in the soil surface (or on the ground surface, in case of rice fields), the
surplus water is considered surface runoff and removed from the field. However, the surface runoff is not returned to the river, but lost from the model,
even if the irrigation node is connected to a river with a return flow channel.
A.3.5.2 Available Runoff models
Four surface runoff model options are available:

None

Linear, available for all crops (i.e. for all types of Soil model)


Modified SCS, available for all crops except rice (i.e. for all types of Soil
models except the ZIMsched for Rice field)
Modified SCS for Rice field available only in combination with the ZIMshed for Rice field Soil model
None
No runoff model option applied.
Linear
The linear runoff model assumes a linear relationship between the rainfall
[mm] and the amount of surface runoff. The runoff will be generated according to two specified linear formulas, valid when the accumulated rainfall is
above or below a given threshold. The parameters for the linear model are:

When Rainfall is lower than. It is the threshold of the accumulated rainfall [mm] on the field below which runoff occurs. In this case the runoff
follows the formula specified in the line below:
Runoff = linear coefficient [ ] (fraction to be inserted in the formula) x
Rainfall + constant (to be inserted in the formula) in [mm]

When Rainfall is greater than. It displays the threshold of the accumulated rainfall [mm] on the field above which runoff occurs. If the rainfall is
above the threshold, the runoff follows the formula specified in the line
below:
Runoff = linear coefficient [ ] (fraction to be inserted in the formula) x
Rainfall + constant (to be inserted in the formula) in [mm]
Regardless of the specified parameters, the runoff will never be negative.
199
Irrigation
Note: When including the Linear runoff model, for any crop including rice, setting both coefficients in the linear equation to zero will have the same effect
as not including a surface runoff model. In that case, any excess surface
water will to return to the river.
Modified SCS
The parameters to be specified for the Modified SCS runoff model are:


Soil moisture integration depth. The soil moisture integration depth
[m] which has an influence on the infiltration losses in the modified SCS
model.
Coefficient of initial abstraction. This coefficient determines also the
infiltration losses.
When this runoff model is selected, the surface runoff is estimated using the
Soil Conservation Service (SCS) storm flow equation (USDA, 1985) /4/ as
modified by Schulze (1995) and used in the ACRU agrohydrological simulation model in South Africa.
The modified equation is given by:
2
P – c  S
Q = ----------------------------------P + S  1 – c
(A.3.6)
Where:
Q: Surface runoff [mm]
P: Rainfall [mm]
c: Coefficient of initial abstraction (default value 0.25) [-]
S: Potential maximum water retention of the soil, taken as the soil water deficit below porosity over the depth Zinte [mm]
Zinte: Integration depth (default Zinte = 0.25 m) [m]
S is calculated from the following formulas:
For Zinte  Ze :
S =  sat – e   Ze  1000 +  sat – root    Zinte – Ze   1000
For Zinte  Ze :
S =  sat – e   Zinte  1000
Where:
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MIKE HYDRO - © DHI
Runoff Model
sat : Water content at saturation [-]
e : Water content in the Top Soil [-]
root : Water content in the Root Zone [-]
Ze: Depth of the Top Soil layer [m]
Example:
Input P = 100 mm, Soil moisture integration depth = 0.2 m.
Porosity = 0.45, and actual soil moisture content is equal to 0.20.
The runoff is calculated from:
2
P – c  S
Q = ---------------------------------P + S  1 – c
For C= 0 and S = 50 mm Q = 67 mm
For C=0.5 and S = 50 mm, Q = 45 mm
Modified SCS for Rice field
The difference between the Modified SCS for Rice field model and the Modified SCS model is that the space (storage) between the maximum ponded
water depth (see the ZIMsched for Rice field model section) and the actual
water depth is also taken into account in the calculation of the water volume
of the potential maximum water retention of the soil, S.
In addition, excess water above the maximum ponded water depth at the end
of a time step will be added to the already calculated surface runoff (can only
occur when a specified irrigation application is used).
The input parameters for the Modified SCS for Rice field model are the same
as those for the Modified SCS.
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Runoff Model
A.4
References
/3/
Allen, R.G., Pereira, L.S., Raes, D. and Smith, M., 1998. Guidelines
for computing crop water requirements. FAO Irrig and Drainage
Paper No. 56, FAO, Rome, Italy.
/4/
USDA, 1985. National Engineering Handbook, Section 4, Hydrology. United States Department of Agriculture (USDA), Soil Conservation Service, Washington DC, USA
203
References
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APPENDIX B
205
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Prediction of reservoir trap efficiency
B.1
Reservoir sedimentation in MIKE HYDRO Basin
B.1.1 Prediction of reservoir trap efficiency
In MIKE HYDRO Basin a reservoir is characterised by the following:

A (surface) area elevation curve/table

Top of dead storage level

Bottom level

Dam crest level (optional)

Spillway Discharge/water level (Q/H) relation

Spillway spill level

Spillway bottom outlet
MIKE HYDRO Basin determines at each time step the reservoir inflow and
outflow (distributed on outlets at level of dead storage and spillway), as well
as the reservoir water level, volume and surface area.
The reservoir sediment trap efficiency is determined in a number of steps.
First the reservoir retention time T can be calculated as reservoir volume (V)
divided by inflow (Qi), i.e.
V
T = ------Q1
The retention time indicates how long water on average will stay within the
reservoir.
The trap efficiency (TE) for each size fraction i, with a settling velocity wi, can
then be calculated as (see Chen 1975):
wi T
TE i = 1 – e -------D
In which D is a characteristic reservoir water depth (calculated from storage
elevation curve). D may be calculated as
Vr
D = -------------A r surf
Where Vr is the instantaneous volume of water in the reservoir and Ar,surf is
the instantaneous surface area of the reservoir. Thus the characteristic depth
is equivalent to the average depth in the reservoir.
The trap efficiency indicates the fraction of sediment that is deposited in the
reservoir. The total sediment deposited is calculated as
N
Deposition =
 TE i Qi load
i=1
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Reservoir sedimentation in MIKE HYDRO Basin
The sediment transport of each size fractions released downstream (and thus
used in the routing calculation) is given by
Q i load out =  1 – TE i  Q i load in
B.1.2 Update of reservoir storage surface curve
A storage volume elevation curve is constructed from the storage area elevation curve. The assumption is that the storage area varies linearly between
the given elevations.
Thus for a given storage elevation area tabulated curve, the reservoir volume
column will be calculated by MIKE HYDRO Basin.
Table B.1.1
Calculated reservoir volume
Elevation
Reservoir Surface Area
Reservoir Volume
hN
AN
VN
hN-1
AN-1
VN-1
...
...
...
hi+1
Ai+1
hi+1
hi
Ai
hi
hi-1
Ai-1
hi-1
...
...
...
h1
A1
h1
h0
A0
h0
The surface area varies between levels hi and hi+1 as
 Ai + 1 – Ai 
A = A i +  h – h i  --------------------------- hi + 1 – hi 
The volume varies between the levels hi and hi+1 as
1
2  Ai + 1 – Ai 
V = V i + A i  h – h i  + ---  h – h i  ---------------------------2
 hi + 1 – hi 
Which for h=hi+1 reads
i
1
1
V i + 1 = V i + ---  A i + 1 + A i   h i + 1 – h i  = ---   A j + 1 – A j   h i + 1 – h i 
2
2
j=0
To update the storage area curve requires the calculation of a dimensionless
quantity F which signifies the amount of deposited sediment volume above
the reservoir volume relative to the total volume of a cylinder formed reservoir
with surface area given by the current level
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Update of reservoir storage surface curve
S–V
F = -------------HA
Where S is the total volume deposited sediment within the considered timespan. H is the maximum depth for a full reservoir i.e.
H = hN – h0
The relative depth p is calculated as
h–h
p = --------------0H
The user selects the curve (I, II, III, IV) (see Morris & Fan (1997) p. 10.3210.39) of corresponding values of (p,F). The intersection with the curve made
up of the calculated set of values (p,F) is determined. The intersection is
denoted (pin,Fin) and the value of pin indicates the so-called zero capacity elevation. The corresponding values of reservoir area and volume are calculated
through the formula given earlier. The zero-capacity level indicates the new
bottom level of the reservoir.
The relative sediment area is calculated from the equation below for each of
the elevations (including the zero capacity level)
c1
a = c0 p  1 – p 
c2
Where the coefficients (c0,c1,c2) depend on the reservoir type selected (I, II,
III, IV) (Morris and Fan (1997)). The relative sediment area at the zero capacity level is denoted by ain . The area occupied by the sediment at the various
levels is determined from
ai
A sediment i = A in -----a in
Where Ain is the surface area at the zero capacity level and the area occupied
by the sediment is only calculated above the zero capacity level (below this
level the reservoir is assumed to be filled). The sediment volume may be
evaluated as
1
V sediment i + 1 = V sediment i + ---  A sediment i + A sediment i + 1   h i + 1 – h i 
2
The revised storage area is determined as
A revised i = A i – A sediment i
The revised storage volume is given by
V revised i = V i – V sediment i
Below the zero capacity level the both the storage area and the storage volume are set to zero
The storage elevation curve is updated at regular intervals (typically different
from the time step). The interest lies in the time as to when the bottom of the
209
Reservoir sedimentation in MIKE HYDRO Basin
reservoir reaches the top of the dead storage level. At this point the reservoir
will quickly fill and after this point the inflow will be equal to the outflow.
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INDEX
211
Index
A
Allocation pool reservoirs . . . . . 128, 134
Autocalibration . . . . . . . . . . . . . 91
B
Background layers . . . . . . . .
Background maps . . . . . . . .
Basin modules . . . . . . . . . .
Bifurcation node . . . . . . . . .
Bifurcation table . . . . . . . . .
Bifurcation time series . . . . . .
Bottom level . . . . . . . . . . .
Bottom outlet capacity time series
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. 56
. 56
. 49
. 67
. 67
. 67
. 81
. 142
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. . 91
. . 79
. . 78
. . 77
. . 75
. . 129
. . 54
. . 134
. . 35
. . 55
17, 43
. . 75
. . 35
. . 37
. . 35
. . 61
. . 117
. . 118
. . 117
C
Calibration parameters . . . . . .
Calibration plot . . . . . . . . . .
Catchment area . . . . . . . . . .
Catchment properties . . . . . . .
Catchments . . . . . . . . . . . .
Characteristic levels time series .
Computational control parameters
Conservation zone . . . . . . . .
Controls . . . . . . . . . . . . . .
Coordinate system . . . . . . . .
Create a new document . . . . .
Create Catchment . . . . . . . .
Create new dfs0 file . . . . . . .
Create new table file . . . . . . .
Create new time series file . . . .
Create River network . . . . . . .
Crop models . . . . . . . . . . .
Crop stages . . . . . . . . . . . .
Crops . . . . . . . . . . . . . . .
D
Deficit distribution methods . . . . .
Delineated catchments . . . . . . .
Demand carry-over fraction . . . . .
Demo . . . . . . . . . . . . . . . .
Derive the River network from a DEM
Digitising a River network . . . . . .
.
.
.
.
. 110
. 76
. 104
. 39
. 63
. . 62
E
Elevation zones . . . . . . . . . . . . . 86
F
FAO 33 Yield model
212
FAO 56 Dual Crop Coefficient model .
FAO 56 irrigation method . . . . . . .
FAO 56 soil water model . . . . . . . .
Flood control zone . . . . . . . . . . .
Flow capacity time series . . 66, 107,
Flow loss time series . . . . . 66, 107,
118
115
122
133
140
139
G
General tab . . . . . . . . . . . 63, 78,
Global parameters . . . . . . . . . . .
Groundwater . . . . . . . . . . . . . .
Groundwater model . . . . . . . . . .
Groundwater options . . . . . . . . . .
Groundwater properties . . . . . . 80,
Groundwater recharge time series . . .
Groundwater use time series . . . . . .
128
.49
.90
.78
104
104
.81
105
H
Hydropower plants properties
. . . . . 148
I
Importing a River network .
Inactive (Dead storage) zone
Initial conditions . . . . . .
Initial water table depth . . .
Insert a Hydropower plant .
Insert Reservoir . . . . . .
Insert Water user . . . . . .
Inspect Results . . . . . . .
Irrigated field . . . . . . . .
Irrigation . . . . . . . . . .
Irrigation Data . . . . . . .
Irrigation method . . . . . .
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.62
134
.90
.81
147
127
102
.45
111
.88
113
113
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128,
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132
129
.70
125
129
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.73
.22
.68
126
.71
L
Lakes . . . . . . . . . . . .
LAV table . . . . . . . . . .
Linear reservoir routing . . .
Linear runoff model . . . . .
Losses and gains time series
M
Manning formula . . . . .
Map view . . . . . . . . .
Minimum flow time series
Modified SCS runoff model
Muskingum routing . . . .
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. . . . . . . . . . 120
MIKE HYDRO - © DHI
Index
N
S
NAM . . . . . . . . . . . . .
NAM model . . . . . . . . .
Normal operating zone . . .
Nursery’ phase . . . . . . .
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. 49
. 82
134
119
O
Objective functions . .
Open Examples . . . .
Outlet depth . . . . . .
Output window . . . .
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32,
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92
39
81
25
Pool ownership time series
Power demand time series
Priority . . . . . . . . . . .
Priority nodes . . . . . . .
Properties view . . . . . .
Properties window . . . . .
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Rainfall runoff time step length
Rainfall-runoff . . . . . . . . .
Rainfall-runoff model . . . . .
Rating Curve approach . . . .
Reduced operating zone . . .
Reduction levels . . . . . . . .
Remote flow control . . . . . .
Reservoir properties . . . . . .
Reservoir type . . . . . . . . .
Reservoirs . . . . . . . . . . .
Result file-types . . . . . . . .
Results specifications . . . . .
Results tree view . . . . . . .
Rice Crop Irrigation method . .
Rice Crop model, . . . . . . .
River basin management . . .
River network . . . . . . . . .
River nodes tab . . . . . . . .
Routing . . . . . . . . . . . .
Rule curve reservoirs . . . . .
Run Simulation . . . . . . . .
Running the autocalibration . .
Runoff model . . . . . . . . .
Runoff parameters . . . . . .
Runoff time series . . . . . . .
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. . . . 53
. . 49, 82
. . . . 79
. . . . 73
. . . 134
. . . 136
. . . 140
. . . 127
. . . 128
. . . 127
. . . 170
. . . 169
. . . . 22
. . . 116
. . . 119
. . . . 53
. . . . 61
. . . . 66
. . . . 69
. 128, 133
. . . . 45
. . . . 92
. . . 124
. . . . 83
. . . . 79
P
138
148
135
. 67
. 22
. 24
R
Schematic Catchments . . . . .
Seasonal variation . . . . . . .
Sediment distribution type . . .
Sediment properties . . . . . .
Set up a simple model . . . . .
Settling velocities . . . . . . . .
Setup tree view . . . . . . . . .
Simulation description . . . . .
Simulation period . . . . . . . .
Simulation specifications . . . .
Simulation tab . . . . . . . . . .
Snow Storage . . . . . . . . . .
Soil and Runoff model . . . . .
Soil model . . . . . . . . . . . .
Spill capacity table . . . . . . .
Spillway bottom level time series
Spillways . . . . . . . . . . . .
Storage demand . . . . . . . .
Storages . . . . . . . . . . . .
Storing Results . . . . . . . . .
Supply Catchment . . . . . . .
Supply connections tab . . . . .
Surface and rootzone . . . . . .
Surface-rootzone . . . . . . . .
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. 76
. 93
. 130
. 160
. 43
. 160
. 19
. 51
. 52
. 47
. 25
. 90
. 121
. 121
. 142
. 142
. 141
. 141
. 83
. 169
. 105
. 106
. 90
. 83
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T
Time constants .
Time series . . .
Time series tab .
Time Step Control
Tree view . . . .
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81
93
26
53
18
UHM . . . . . . . . . . . . .
UHM (Unit Hydrograph) model
UHM parameters . . . . . . .
User Interface . . . . . . . . .
Users tab . . . . . . . . . . .
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49, 95
. . 95
. . 95
. . 18
. . 135
U
V
Validate setup . . . . . . . . . . . . . . 45
Validation tab . . . . . . . . . . . . . . 25
W
Water demand . . . . . . . . . . . . . 103
Water demand time series . . . . . . . 103
Water level calculation . . . . . . . . . 72
213
Index
Water user properties
Water user type . . .
Water users . . . . .
Wave translation . .
Working area . . . .
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. 102
. 103
. 101
. 72
. 58
Y
Yield model . . . . . . . . . . . . . . . 120
Z
ZIMsched soil water model . . . . 122, 124
214
MIKE HYDRO - © DHI
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