MIKE Flood River- Exercises

MIKE FLOOD TRAINING Modelling of River Flooding Exercises

MIKE BY DHI 2011

Agern Allé 5 DK-2970 Hørsholm Denmark Tel: +45 4516 9200 Support: +45 4516 9333 Fax: +45 4516 9292 [email protected] www.mikebydhi.com

2011-08-12/DOCUMENT1/JSL/2011Training.lsm

Agern Allé 5 DK-2970 Hørsholm Denmark Tel: +45 4516 9200 Support: +45 4516 9333 Fax: +45 4516 9292 [email protected] www.mikebydhi.com

2011-08-12/DOCUMENT1/JSL/2011Training.lsm

CONTENTS

Modelling of River Flooding Exercises

1

INTRODUCTION .............................................................................................. 1

1.1 1.2 1.3

Background .......................................... ................................................................ ............................................ ............................................. ....................................... ................1 MIKE FLOOD Project Presentation ........................................................ ............................................................................... ............................... ........ 1 Required Data......................................................... ................................................................................ .............................................. .......................................... ...................3

2

PROJECT AND DATA PREPARATION IN MIKE ZERO ........................ ............................ .... 5

2.1 2.1.1 2.2 2.3 2.4

Creating a New Project from Template ........................................... .................................................................. ....................................... ................5 Change the Settings for Project Explorer ......................................... ............................................................... ....................................... .................7 Convert XYZ Data for Project .................................................. ........................................................................ ............................................ ........................ .. 7 Create a DFS0 Water Level Time Series from ASCII File ............................................. ..................................................... ........ 8 Create Hydrograph Time Series for Project ............................................. .................................................................... ............................. ......10

3

SETTING UP A MIKE 11 MODEL FOR MIKE FLOOD ................ ......................... ............. .... 13

3.1 3.1.1 3.1.2 3.1.3 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.3

Review the Existing MIKE 11 Model “whole” “ whole” .......................................... ................................................................. .......................... ... 13 Check the Simulation File ....................................... ............................................................. ............................................ ........................................ ..................13 Open the MIKE 11 Input Files ........................................... ................................................................. ............................................ ............................. .......14 Edit the Network File ................................................. ....................................................................... ............................................ ..................................... ...............17 Prepare the MIKE 11 Model for MIKE FLOOD ............................................ .................................................................. ......................20 Edit the Network and Boundary Files ............................ .................................................. ............................................. ................................. ..........20 Modify the Cross-Section File ............................................................. ................................................................................... ................................. ...........22 Update the Simulation Parameters ................................................... .......................................................................... ..................................... ..............26 Create another MIKE 11 Setup .................................. ........................................................ ............................................. ..................................... ..............26 View MIKE 11 Results in MIKE VIEW .................................................... ........................................................................... .......................... ... 27

4

SETTING UP A MIKE 21 MODEL ................................................................ 29

4.1 4.1.1 4.1.2 4.1.3 4.1.4 4.1.5 4.2 4.2.1 4.2.2 4.2.3 4.2.4

Defining the Model Topography........................................... .................................................................. ............................................. ......................... ... 29 Create a Bathymetry File ........................................... ................................................................. ............................................ ..................................... ...............29 Import Background Back ground Data and Image to t o Bathymetry File ................................. ...................................................... .....................31 Create and Export the Bathymetry ............................. ................................................... ............................................. ..................................... ..............33 Import Topography from ASCII File ................................. ....................................................... ............................................. ............................. ......37 Create Palette and Overlay for Project ....................... ............................................. ............................................. ..................................... ..............39 Creating the Bathymetry dfs2 Files for MIKE 21 Model .................................... ..................................................... .................46 Create Grid50m_2.dfs2 for MIKE FLOOD Model ............................................ .............................................................. ..................46 Create Grid50m_3.dfs2 for MIKE FLOOD Model ............................................ .............................................................. ..................49 Create Grid50m_4.dfs2 for MIKE FLOOD Model ............................................ .............................................................. ..................51 Create an Initial Water Level Map for MIKE FLOOD Project ............................................ ............................................51

i

4.2.5 4.3 4.3.1 4.3.2 4.3.3

Create a Roughness Map for MIKE FLOOD Project ........................................................... 53 Setup of Different MIKE 21 Flow Models for MIKE FLOOD Project ............................... 54 Create a Standalone MIKE 21 Flow Model .......................................................................... 54 View the MIKE 21 Result File in Grid Editor ...................................................................... 59 Create 2D Component for MIKE FLOOD Model 1 ............................................................. 60

5

COUPLING AND RUNNING MIKE FLOOD MODEL 1: ASSESSMENT OF EXPLICIT COUPLES ............................................................................... 61

5.1 5.2 5.3 5.4 5.5 5.6

Create a New Couple File for MIKE FLOOD 1 ................................................................... 61 Create 2 Standard Links ........................................................................................................ 63 Create a Lateral Link for “Tributary” ................................................................................... 65 Block Out River Cells in the Bathymetry File ...................................................................... 68 View the MIKE FLOOD 1 Results in Plot Composer .......................................................... 70 Additional, if time permits… ................................................................................................ 71

6

CREATE DIFFERENT MIKE FLOOD MODELS FOR COMPARISON .... 73

6.1 6.1.1 6.1.2 6.2 6.2.1 6.2.2 6.2.3 6.2.4 6.2.5 6.3 6.3.1 6.3.2 6.3.3 6.3.4

Create MIKE 21 Models for MIKE FLOOD........................................................................ 73 Create 2D Component for MIKE FLOOD Model 2 ............................................................. 73 Create 2D Component for MIKE FLOOD Model 3 ............................................................. 73 MIKE FLOOD 2: Assessment of Implicit Couples/Structures ............................................. 74 Create MIKE FLOOD 2 Couple File .................................................................................... 74 Modify the MIKE 11 Model to Insert an H-Q-H Structure Branch ..................................... 74 Set up the Implicit Structure in MIKE FLOOD 2................................................................. 81 Add Zero Flow Links ............................................................................................................ 84 View and Analyse the Results of MIKE FLOOD 2 ............................................................. 84 MIKE FLOOD 3: Assessment of Explicit Structures ........................................................... 87 Create MIKE FLOOD 3 Couple File .................................................................................... 87 Insert an H-H Structure Branch in MIKE 11 ........................................................................ 87 Define Explicit Links for H-H Conduit in MIKE FLOOD 3................................................ 92 View the Results of MIKE FLOOD 3 .................................................................................. 93

7

DISCUSSIONS ................................................................................................ 95

7.1 7.2 7.3

H-Q-H versus H-H Structure Method ................................................................................... 95 Implicit versus Explicit Structure Methods .......................................................................... 95 Tips to Improve the Stability of the Links ............................................................................ 97

8

RESULT EXTRACTION USING TOOLBOXES .......................................... 99

8.1 8.2 8.3

MIKE Zero Toolbox ............................................................................................................. 99 MIKE 21 Toolbox ............................................................................................................... 102 Additional Result Viewing Tools ....................................................................................... 104

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MIKE FLOOD Training

Introduction

1

INTRODUCTION

1.1

Background The purpose of these exercises is to construct different coupled MIKE FLOOD models (MIKE 11-MIKE 21) going through all the necessary steps. The exercises relate to a typical example of applying MIKE FLOOD to simulate water levels across a floodplain on the East Coast of Australi a. The scenario is presented as follows:

1.2

•

A MIKE 11 model of the river and floodplain exists

•

New 2D ground data (ALS or LIDAR) has been sourced

•

A MIKE 21 model of the floodplain needs to be developed

•

Four MIKE FLOOD models, utilizing the existing MIKE 11 model, will be created to determine impacts of road upgrades and new structures on flood levels.

MIKE FLOOD Project Presentation Through the exercises of this training guide, you will setup various models for the MIKE FLOOD Project. A list of the different models is presented below:

Exercises

•

A standalone MIKE 11 model with a Main River and a Tributary (“whole”);

•

A standalone MIKE 21 model which replicates the MIKE 11 model (“standalone”);

•

MIKE FLOOD Model 1 to be used for assessment of expli cit links;

•

MIKE FLOOD Model 2 to be used for assessment of implicit links/structures;

•

MIKE FLOOD Model 3 to be used for assessment of explicit structures;

1

Modelling of River Flooding

Standalone MIKE 11

Standalone MIKE 21

MIKE FLOOD 1: Explicit couples

MIKE FLOOD 2: Implicit Structure (HQH)

MIKE FLOOD 3 (left): Explicit Structure (HH Conduit)

2

MIKE FLOOD Training

Introduction

1.3

Requir ed Data The available data for this exercise are stored under the “exercises” folder. Data are placed in 5 sub-folders. These include: •

COUPLE Topo.pfs – palette for MIKE FLOOD Couple.xls – spreadsheet of all coupled cells used in exercises

•

DFSO Hydrograph.xls – spreadsheet with base inflow hydrograph Tide.txt – ASCII file used to create time series of tide Test.dfs1 – example of DFS1 file for exercises

•

MIKE 11 Existing model setup “whole” including 5 files (sim11, bnd11, HD11, nwk11, xns11) Photo.jpg – background image for MIKE 11 Photo.extents – text file of image coordinates Create Closed Sections 1.xls – tool for making conduit section

•

MIKE 21 Photo.bmp – background image for MIKE21 Photo.bmpw – text file of image coordinates Test_lat.xyz – raw XYZ point in lat/long coordinates \ASCII Files: Ascii_Import.txt – DHI ASCII format for import of grid data Ascii_toolbox.asc – ESRI ASCII format for grid data \Backup Grids: Backup grids of bathymetry, roughness and initia l conditions

•

RESULTS Comparison.xls – spreadsheet of results comparing methods Exercise.plc – plot composer for exercise M21_Toolbox.21t – M21 toolbox for exercise MZ_Toolbox.mzt – MZero toolbox for exercise

Check to make sure you have all of these files prior to starting.

Exercises

3


4

MIKE FLOOD Training

Project and Data Preparation in MIKE Zero

2

PROJECT AND DATA PREPARATION IN MIKE ZERO

2.1

Creating a New Projec t from Temp late The first step in creating a new MIKE FLOOD model is to create a MIKE Zero project.

Exercises

1

Start MIKE FLOOD by selecting Start/Program files/DHI Software/MIKE FLOOD/MIKE FLOOD. This will load the MIKE Zero modelling platform from which you can create or open MIKE 11, MIKE 21 and MIKE FLOOD models.

2

From the MIKE Zero window select File >New > New Project from template…. The following New Project dialog will appear.

3

This dialog provides a selection of typical Project Types and a list of Project Templates for the selected Project Type. As noted in the dialog, the Project Templates provide a suggested folder structure for helping to organise your model data.

4

In the Project Type list, select General, and in the Template list, select the General item.

5

Fill in the Project Name and the Client as indicated in the dialog Name (give a dummy name for this exercise) and then click the [OK] button to create the project folder.

5


The folder structure of the selected project template is listed under the Project Explorer panel on the right-hand side of the MIKE Zero window. This panel provides you with an easily accessible overview of the project and the files associated with the project. 6

Under the folder Model, create three sub-folders named MIKE11, MIKE21 and COUPLE by right-clicking on the folder Model, selecting Add Folder.

7

Similarly, under the Result folder, create two sub-folders named MIKE11 and MIKE21.

8

We now need to reorganise the data and move the files to the relevant folders. You can use Windows Explorer or try the Project Explorer in MIKE Zero: Copy the data from the Data folder into the Model folder. Copy the data under MIKE11 to the Model\MIKE11 folder. Similarly copy the data for MIKE21, COUPLE and DFS0 into the relevant project folders.

9

If you could not see the content of these folders under the Project Explorer just right click on the folder and choose Show All (if it is already checked, uncheck it and recheck it again) then it will refresh. Your Project Explorer should look as follows:

6

MIKE FLOOD Training


2 .1 .1

C h a n g e t h e S e t ti n g s f o r P r o j e c t E x p l o r e r

Go to MIKE Zero > File > Options > User Settings… Under the General Tab, enable “Dynamic Show All”

Browse through the other tabs of the User Settings window. You can specify the default project location, parameters for notifications (SMS and emails), the file associations, etc…

2.2

Con vert XYZ Data for Project In this exercise, we would like to convert spat ial XYZ data coordinates from one coordinate system to another. The XYZ data will be used to create the bathymetry, input to the 2D model.

Exercises

1

Go to MIKE Zero > File > Options > Datum Convert.

2

Navigate to the folder Model\MIKE21 and select the file “test_lat.xyz”.

3

Assign map projection and type of coordinates to System A: MGA-56 (Australian Datum) in Lat/Long (geographical).

7


2.3

4

We want to convert the Coordinate System A into a Coordinate System B, here: MGA-56 in Easting/Northing (Map projection). Click “Convert from A to B”.

5

Save the file as “test_mga.xyz” and close the Datum Converter.

Create a DFS0 Water Level Time Series from ASCII File In this exercise, you will create a time series (*.dfs0) from an ASCII file. This time series will be used as a downstream water level boundary condition in the project.

8

1

Go to MIKE Zero > File > New > File > MIKE Zero > Time Series > From ASCII File.

2

Navigate to Model\Model Inputs\DFS0 and select the file “tide.txt”.

3

Select “Equidistant Calendar Axis”.

MIKE FLOOD Training


4

Exercises

Click OK and save the file as “tide.dfs0” under Model\Model Inputs\DFS0. Close the file.

9


2.4

Create Hydrog raph Time Series for Project We will now create a hydrograph for the project from a blank time series a nd copy the hydrograph data from an Excel sheet. The hydrograph will be used as inflow boundary to the model.

10

1

Open the file “Hydrograph.xls” under Model\Model Inputs\DFS0 and review the file (period, time step, items, units, etc…).

2

Go to MIKE Zero > File > New > File > MIKE Zero > Time Series > Blank Time Series.

3

Fill in the descriptor and start date. Infill time interval and number of time steps as shown on the image below.

4

You need to add 3 different items to this time series. “Append” 3 blank “Discharge” time series and rename them as “Main”, “Trib” and “Main_M21” (see image above). Click OK.

5

You can now see the graphical and tabular view of the time series data. Copy the data from the Excel sheet into the first column “Main”.

6

Use the Calculator (Tools > Calculator) to create data for “Trib” and “Main_M21”: Divide values from column 1 by 5 for “Trib” Multiply values from column 1 by -1 for “Main_M21”

MIKE FLOOD Training


Exercises

11


7

12

Save the file as “Inflow.dfs0” under Model\Model Inputs.

MIKE FLOOD Training

Setting Up a MIKE 11 Model for MIKE FLOOD

3

SETTING UP A MIKE 11 MODEL FOR MIKE FLOOD The aim of the present exercise is to review the existing MIKE 11 model setup and change some graphical settings so that you will get familiar with the different files and features of MIKE 11. Hereafter, you are going to modify the 1D model for use in the MIKE FLOOD setup.

3.1

Review the Existing MIKE 11 Model “ w hole”

3.1.1

Check the Simu lation File

1

Exercises

Open MIKE Zero and load your Project if it is not alread y open. From the Project Explorer, navigate to Model\MIKE11 and double click on “whole.sim11” to load the simulation file. Alternatively, you can load the simulation by going to File > Open > File and browse to the *.sim11 file.

13


2

3.1.2

Check each tab in the *.sim11 file successively: Models Tab where you select the MIKE 11 modules to execute and the simulation mode. Input Tab where you specify the required input file names to run the model. Simulation Tab which contains details of simulation time, time stepping specifications and initial conditions for each of the chosen models. Results Tab where you specify a file name for saving results of each simulation. Change the file path name to the Result\MIKE11 directory of your project. Start Tab where you can start the simulation. If all specified input files exist (green validation status), the “Start” button can be pressed to run the simulation. Some files may need to be reloaded as the file path may have changed.

Open the MIKE 11 Inpu t Files

From the Input Tab of the Simulation file, you can open all input files specifi ed for the simulation by pressing “Edit…”. 1

Open the Network file.

Inflow Boundary (Main)

Source Inflow (Trib) Inflow Boundary (Trib)

2

14

Level Boundary

Open the Cross-section file.

MIKE FLOOD Training

Setting Up a MIKE 11 Model f or MIKE FLOOD

Exercises

3

Open the Boundary file. You may need to reload the boundary time series as they are stored in a new directory \Model\Model Inputs.

4

Open the HD Parameter file.

15


5

16

Go back to the simulation file and run the model.

MIKE FLOOD Training


3.1.3

Exercises

Edit the Netwo rk File

1

Open the network file from the Input Tab of the simulation file .

2

On the graphical view, look at the various digitisati on tools. You can try and draw points, add a branch, etc… Remember not to save the network file or do not forget to rename it before.

3

Open the Tabular View of the network editor. Go to View > Tabular View or press [Ctrl] + [t] on the graphical view. Click on the tree view on the left to navigate through the different network tables (Points and Branches).

4

We would like to add a background image to the graphical view. Go to Layers > Add/Remove. Load the picture “Photo.jpg” from Model\MIKE11.

17


18

5

The picture does not display properly so we need to define the extent of the coordinates. Go to Layers > Properties and insert the image coordinates: Min X: 500543 Max X: 511994 Min Y: 7049718 Max Y: 7069277

6

Save the file and close all files from the “whole” model.

MIKE FLOOD Training


Exercises

19


3.2

Prepare the MIKE 11 Mod el for MIKE FLOOD You will now edit the existing MIKE 11 setup so that it can be used with MIKE FLOOD.

3 .2 .1

1

Open the “whole.sim11” file and save it as “mflood1.sim11” in the s ame project folder.

2

Open all 4 referenced files and rename them as follows: mflood1.nwk11 mflood1.xns11 mflood1.bnd11 mflood1.hd11

3

Reassign the new files to “mflood1.sim11” and save the simulation file.

E d i t t h e N e t w o r k a n d B o u n d a r y F i l es

1

20

Open the network file. We would like to add a grid file as a background image. Go to Layers > Add/Remove. Load the grid file “Grid50m_2.dfs2” from External Data\MIKE21\Backup Grids. Turn off the aerial photo in Layers > Properties and t urn on the grid file instead (double-click to select or unselect a layer).

MIKE FLOOD Training


2

Now, we need to remove a few items by right-clicking on the graphical view: The tidal boundary at the outlet of Main River (to the East). Right-click on the outlet and choose “Delete”, delete the boundary. The point source inflow to Main River directly from the boundary file. The branch connection between “Main River” and “Tributary” using the “Disconnect Branch” tool.

3

Split the branch “Main River” downstream of chainage 5831 m using this “Cut branch into 2” tool

. Delete the lower part of the branch and the

points left behind using the following tools and . You can also delete the branch at once from the tabular view. This part of the branch will be modelled in MIKE 21 instead. 4

Exercises

Add new water level boundaries at the loose ends of the new network. The boundary should be a constant water level of 0m. To add a boundary, rightclick on the graphical view and choose Insert > Boundary > Hydrodynamic… you should now have 4 boundaries: 2 inflow boundaries and 2 water level boundaries at the downstream ends.

21


3.2.2

22

Mod ify the Cros s-Section File

1

Open the cross-section file “mflood1.xns11”

2

Copy the cross-section at “Tributary” chainage 3437m to chainage 3500m. Right click on the cross-section on the tree view and choose Copy…

MIKE FLOOD Training


3

Exercises

Trim the “Tributary” cross-sections cross -sections to the low flow channel using the bank markers 1 and 3 from chainage 3500m to chainage 10065m.

23


24

4

Rename the cross-section cross-section at “Tributary” “Tributar y” ch6835m to ch6850m by rightright clicking on the cross-section in the tree t ree view.

5

Insert an interpolated cross-section cross-section at “Tributary” “Tributar y” ch10000m by using the right-click function.

6

Insert interpolated cross-sections cross-sections at 50m intervals on branch “Tributary” between ch3500m and 10000m. 10000m. Having a cross-section section every 50m will ensure at least one H-point H -point every 50 metres for a better coupling with MIKE 21 (bathymetry with 50 m grid resolution).

MIKE FLOOD Training


Exercises

7

Using the option “Apply to All Sections” Sections” (from the menu Cross-sections) Cross-sections) change the Type and Process Data for all sections se ctions as shown below. Save the cross-section file.

8

Open the network file and view the changes in the graphical view. Open the tabular view and generate the grid points. Save the network file.

25


Changing dX to 50 m in Branch Menu will have same effect as Interpolated Sections (more H-Points)

3.2.3

3.2.4

Upd ate the Simu lation Parameters

1

Close the cross-section and network files and go to the simulation file “mflood1.sim11”.

2

Change the simulation time step to 5 sec. This is the time step we will use in the MIKE 21 setup.

3

Change the result file name to “mflood1.res11”, save it under the directory Result\MIKE11 and change the saving interval to 120 time steps.

4

Save the simulation file and check that the model runs.

Create ano ther MIKE 11 Setup

Now that you have created a MIKE 11 model for MIKE FLOOD “mflood1.sim11”, rename all the files to “mflood2.sim11”. Do not forget to also change the result file name to “mflood2.res11”. This second MIKE 11 setup will be used for another MIKE FLOOD model.

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MIKE FLOOD Training


3.3

View MIKE 11 Results in MIKE VIEW You can view MIKE 11 result file (*.res11) using MIKE View. To start M IKE View, go to Start > Programs > MIKE BY DHI 2011 > MIKE View > MIKE View.

Exercises

1

Open MIKE View and navigate to the \Results director y. Open “whole.res11”.

2

View the results using different tools: time series graph of water level and discharge results time series data longitudinal profile q/H curve water level in a cross-section

3

Use the animation tool to animate a longitudinal profile and a cross-section.

27


4

28

Exit MIKE View.

MIKE FLOOD Training

Setting Up a MIKE 21 Model

4

SETTING UP A MIKE 21 MODEL The aim of the present exercise is to construct the 2D component of the coupled 1D/2D MIKE FLOOD setup.

4.1

Defining the Model Topog raphy The topography is the most important data for creating a 2D model. This is the driven force for overland flow. In this exercise, we are going to use the Bathymetry Editor to process xyz survey data to generate the bathymetry.

4.1.1

Exercises

Create a Bath ym etry File

1

Open a new bathymetry file by going into MIKE Zero > File > New > File > MIKE Zero > Bathymetries (.batsf).

2

In the Define Working Area dialog, enter the coordinates, projection and origin data as indicated in the figure below. Then click t he OK button to validate the values.

29


3

30

Save the bathymetry file as “test.batsf” under Model\Model Inputs. In the Define Working Area dialog, enter the coordinates, projection and origin data as indicated in the figure below. Then click the O K button to validate the values.

MIKE FLOOD Training


4 .1 .2

Exercises

Im p o r t B a c k g r o u n d D a ta a n d Im a g e t o B a t h y m e t r y F i l e

4

Navigate to Model\MIKE21 and open the file “Photo.bmpw”. Review the coordinates of the image.

5

From the top menu bar select Working Area > Background Management to open the Background Management dialog. Then click the Import button and browse to the file “Photo.bmp”.

6

In the same way, import the data file “test_mga.xyz”. Remember to select “Convert from MGA-56” when importing (“No conversion” should be the default option).

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7

32

Click OK and an image similar to the one below s hould appear. The image shows the location of the available data points to use for creating a model bathymetry data set. Notice that the image is not shown.

MIKE FLOOD Training


4 .1 .3

8

To show the image in the background, simply go to Work Area and select Show Background Images.

9

Save the file.

C r e at e a n d E x p o r t t h e B a t h y m e t r y

We now need to convert the data points for interpolation of the bathymetry. This is done through the following steps: 1

Exercises

Go to Work Area > Bathymetry Management > New.

33


2

34

Define the extent of the grid to be created by entering the values shown in the image below. Click OK.

MIKE FLOOD Training


Exercises

3

Go to Work Area > Settings and change the border display to a tick red line for viewing purposes.

4

Click on the button Import From Background and select all the points by left clicking and holding the left mouse button and then dragging a box around all the points within the working area.

5

Click again on the the image below.

button. The Bathymetry Editor should look similar to

35


36

6

In Work Area > Bathymetry Management dialog, select the previously defined bathymetry item and click the Interpolate button to interpolate the xyz survey data to the bathymetry grid. Set the search radius to 2 and select Bilinear Interpolation method. Leave the other settings as default. Click OK to execute.

7

Save the file. This should create 3 files: the *.batsf file, *.RD file (binary file with raw data) and the *.dfs2 bathymetry grid file. Alternativel y, in the Bathymetry Management dialog, select Export and export the grid file as “Grid50m_1.dfs2” under Model\MIKE21.

MIKE FLOOD Training


8

4 .1 .4

Open and inspect the newly generated grid file.

Im p o r t T o p o g r a p h y f r o m A S C II F i l e

It is also possible to create a bathymetry by importing an ASCII file. Through the steps below, you will learn how to import from an ASCII file. However the file created will not be used for the MIKE FLOOD project.

Exercises

1

Open MIKE Zero and go to File > New > File > M IKE Zero > Grid Series (.dfs2) and choose from ASCII File.

2

Browse to Model\MIKE21\ASCII Files and select the fil e “ASCII_Import.txt”. Click OK.

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38

3

Save the imported file as “Imported_ASCII.dfs2”.

4

It is also possible to import the topography from an ASCII file using MIKE Zero Toolbox. Open MIKE Zero Toolbox from File > New > File > MIKE Zero > MIKE Zero Toolbox (.mzt). Under the GIS Tab, choose Grd2Mike and follow the steps.

MIKE FLOOD Training


4.1.5

Exercises

5

An example has been prepared. Browse to the \Result directory and open “MZ_Toolbox.mzt”. Double click on the setup “Import ASCII” and follow the different steps. Change the result file path to an appropriate folder.

6

Execute the file and open the resulting file “Converted ASCII.dfs2” for review.

Create Palette and Overlay for Project

1

Navigate to Model\MIKE21 and open the bathymetry “Grid50m_1.dfs2”.

2

We want to create a new colour palette to improve the viewing of the bathymetry. Go to View > Palette > New…. to open the Palette Wizard. Fill in the parameters of the first step as indicated on the following image:

39


3

40

Change the colours and values in steps 2 and 3. Follow the next two images. Values go from 10m to -5m.

MIKE FLOOD Training


4

Exercises

Save the palette as “Topo.pal” under Model\MIKE21 by going to View > Palette > Save…

41


42

5

We would like to import the image “Photo.bmp” in the background. We have already reviewed the image coordinates (“Photo.bmpw”) in a previous exercise. Go to Data Overlay > Add/Remove Layers… and load the image file.

6

We need to change the order of display as the image is now hiding the bathymetry. In the Add/Remove Layers dialog go to the tab Overlay Manager and bring the image to the top.

MIKE FLOOD Training


We now want to make the grid transparent so that the image will be displayed in the background, behind the bathymetry. Go to View > Grid Settings… change the Contour type to “Box contour with transparency” and set the transparency to 50%.

The grid should appear like the image below.

7

Exercises

We can also overlay the MIKE 11 network file on top of t he bathymetry. Go to Data Overlay > Add/Remove layers… Browse to the “whole.nwk11” file and select Convert from: MGA-56 before clicking the OK button.

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8

44

Save the grid as “Grid50m_2.dfs2” under Model\MIKE21.

MIKE FLOOD Training


9

Exercises

MIKE Zero created a *.gsf file in the same folder where you have your grid file saved. This file contains information on the grid settings, so that next time you open the grid file, the additional image and network file as well as the palette will be loaded with the grid. Browse to your exercise folder and open the “Grid50m_2.gsf” file for review.

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4.2

Creating the Bathym etry dfs2 Files for MIKE 21 Model In the following steps, you will modify the bathymetry you have created previously to define the topography file to be used in the MIKE FLOOD model. You will also create an initial water level map and a roughness grid.

4.2.1

Create Grid50m _2.dfs 2 for MIKE FLOOD Mod el

In this exercise, we will prepare a second topographic grid for the MIKE FLOOD setup with an ocean boundary and inflow from Tributary 2. The inflow from the Main River and Tributary 1 will be supplied by MIKE 11. 1

Load “Grid50m_2.dfs2” and deselect the image “Photo.bmp” display.

2

Change the transparency of the grid to 0%.

3

The first change to the bathymetry will be to close all boundaries by setting all points along the edge equal to the land value. For the project, t he land value is set to 10m. All points above 10m are considered land. Use the selection tool ( Select by lines) to choose the cells along the boundaries. All the values along the line should be selected and highlighted in the tabular view. From the top menu bar choose Tools > Set value. Enter a value of 10m. Note: once cells are selected, they stay selected until you unselect them by

clicking on the Unselect All icon . If you forget to unselect the cells then all subsequent changes will be applied to all currently selected cells.

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MIKE FLOOD Training


4

Now we would like to block out the ocean cells to the right side of the bathymetry. Use the Select by polygon tool south of the river mouth as shown below.

to select the ocean north and

The current selection is quite rough and includes cells which are not the ocean. We should then refine the selection. Go to Tools > Select > Values… Choose “Select values less than 1” (ocean values are currently around 0m) and apply a filter “Select from the current selection”.

Go to Tools > Set Value and set the value to 10m.

Exercises

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48

5

Using the Selection tool, set the eastern ocean boundary to -3m.

6

Using the Selection tool, create a southern inflow boundary and set the value to -1m.

MIKE FLOOD Training


7

4.2.2

Save the bathymetry file.


In this step, you will create a third bathymetry file “Grid50m_3.dfs2”, it will be used for a standalone MIKE 21 model where all inflows to the model are done through MIKE 21 boundaries.

Exercises

1

Open “Grid50m_2.dfs2” and save it as “Grid50m_3.dfs2”.

2

Using the Selection Tool, create a western inflow boundary as shown on the following image. Set the values to -1m.

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3

50

Using the Selection Tool, create the northern inflow boundary and set the values to -5m. Save the file.

MIKE FLOOD Training


4.2.3


Using the “Grid50m_2.dfs2”, we will define the road embankment across the main river in the grid itself.

4.2.4

Exercises

1

Open “Grid50m_2.dfs2” and save it as “Grid50m_4.dfs2”.

2

Zoom into the road crossing.

3

We would like to insert a road embankment blocking the main river betwee n the existing abutments. For that, select 7 cells using the Selection Tool and set them to 2.6m. (112,60) (112,61) (112,62) (113,63) (113,64) (113,65) (113,66)

4

Save the file.

Create an Initial Water Level Map for MIKE FLOOD Projec t

1

Open the file “Grid50m_3.dfs2” and save it as “Initial50m.dfs2”.

2

Select all values less than 0m by going to Tools > Select > Values… set the selected cells to 0m.

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52

3

Select all points near the southern boundary which are less than the spill level (3.4m) and set them to 3.4m.

4

Save the file.

MIKE FLOOD Training


4.2.5

Create a Rou gh ness Map for MIKE FLOOD Projec t

Finally, we will create the last grid needed for our MIKE FLOOD project: a roughness grid. Different roughness values should be applied to the floodplain and the channels.

Exercises

1

Open “Grid50m_1.dfs2” and save it as “Rough50m.dfs2”.

2

Select all values less than 0m (they should be cells representing the river channels and ocean) and set the value to 40 (Manning‟s n = 0.025).

3

Select all values which are not equal to 40 and set them to 20 (floodplain roughness of Manning‟s n = 0.05).

4

Save the file.

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4.3

Setup of Different MIKE 21 Flow Mod els for MIKE FLOOD Project

4.3.1

Create a Standalo ne MIKE 21 Flow Mod el

1

Create a new MIKE 21 flow model file by selecti ng File > New > File > MIKE 21 > Flow Model (.m21). Save it as “Standalone.m21” under Model\MIKE21.

2

First we will define the Basic Parameters of the MIKE 21 model. Under Module Selection, choose Hydrodynamic only (default). Once you specify the required settings, it will show a green tick icon , otherwise it will show a red cross icon .

3

Under Bathymetry, load the “Grid50m_3.dfs2” file. Once the bathymetry is loaded, you can open it by clicking on the view button open the grid editor.

4

54

and it will

Deselect the “Apply Coriolis forcing”.

MIKE FLOOD Training


Exercises

5

Under the Simulation Period, set the start date to 21/02/1992, the time step to 5 seconds and the number of time steps is 25920 (36hrs).

6

Under Boundary, choose Program Detected (default), it will show that there are 4 boundaries in the model.

7

Under Flood and Dry, assign a drying depth of 0.02m and a flooding depth of 0.05m.

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8

56

You will now continue with the editing of the Hydrodynamic Parameters. Under Initial Surface Elevation, load the map of initial level that you have created “Initial50m.dfs2”, choose “Given as: From File”.

MIKE FLOOD Training


9

Under the Boundary tab, you need to assign boundary time series for each boundary as shown on the image below.

10 The Eddy Viscosity value to be applied is Flux based and 5m 2/s.

Exercises

57


11 Under Resistance, use the roughness map that you have created “Rough50m.dfs2”. 12 In this exercise, you do not need Source and Sink, Wave Radiation, Wind Conditions and Structures. So you can go directly to the Results tab. 13 Under Results, choose 1 output area, type 2 (for 2D). To specify the result file location, press [Ctrl] + [d]. Name the result file as “Standalone.dfs2” in Results\MIKE21. Under J, K and Time, click on the button to specify the output range of the results in term of space and time. We want the results to be saved every 15 min for the entire simulation period and the total grid extent. When you have entered information on the results, you can check the size of the output to be produced. Check that the size is reasonable to you.

14 Save your MIKE 21 model and you are now ready to try and run the model. Go to Run > Start Simulation and click OK in the Launch Setting dialog.

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MIKE FLOOD Training


4.3.2

View the MIKE 21 Result File in Grid Edito r

1

Open the grid result file “Standalone.dfs2”.

2

View the results using the navigation panel and the step forward and back .

3

Exercises

Select different items: H Water Depth, P Flux and Q Flux.

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4.3.3

Create 2D Com po nent for MIKE FLOOD Mod el 1

In this step, you will modify the “Standalone.m21” model to prepare “Mflood1.m21” model which will be used for assessment of explicit couples in MIKE FLOOD model 1.

60

1

Open “Standalone.m21” and save it as “Mf lood1.m21”.

2

Under Bathymetry, use the grid “Grid50m_2.dfs2” as the bathymetry file. A dialog should be prompted asking if you would like to recalculate the boundaries. Click YES as some of the inflow boundaries will be assigned in MIKE 11 instead.

3

You do not need to change anything else under the Basic Parameters. You can go directly under Boundary in the Hydrodynamic Parameters. Reassign the boundaries as indicated on the image below.

4

Under Results, change the result file name to “Mflood1.dfs2”.

5

Save the simulation file and check if it runs (but terminate the simulation).

MIKE FLOOD Training

Coupling and Running MIKE FLOOD Model 1: Assessment of Explicit Couples

5

COUPLING AND RUNNING MIKE FLOOD MODEL 1: ASSESSMENT OF EXPLICIT COUPLES The aim of the following exercises is to couple the 1D and 2D components through the MIKE FLOOD interface and to run the coupled model Mflood1 for assessment of explicit links.

5.1

Exercises

Create a New Cou ple File for MIKE FLOOD 1 1

Create a new couple file by going to File > New > File > MIKE FLOOD and choose MIKE FLOOD (.couple) in document.

2

Click on the Linkage Files Page and browse for the MIKE 21 file “Mflood1.m21”. Load the MIKE 11 file “Mflood1.sim11”. Once you load these 2 files, the overlay of the bathymetry and the river network is shown in the window on the Link Definitions Page.

3

You can change to colour palette of the bathymetry on the Link Definitions Page. Right-click on the graphical view and choose Layer Properties. Click on the Grid file properties and under the Color tab, s elect Open… Load the palette created previously “Topo.pal”. By using the right mouse click, you can also zoom into the bathymetry.

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4

Save the file as “Mflood1.couple” under the folder Model\COUPLE.

In the next steps, you will learn how to couple the 1D and 2D model and create standard and lateral links.

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MIKE FLOOD Training


5.2

Exercises

Create 2 Standard Lin ks 1

On the Definition Page, right-click on the layout and choose “Link river branch to MIKE 21”. In the Link river branch to MIKE 21 dialog, select “Standard link”, “Highest chainage” and connect the “Main River” branch.

2

Repeat the same procedure to link the downstream part of “Tributary” branch.

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64

3

You can now observe the 2 additional lines in the couple table. Notice that when you select the line, the location of the link is highlighted in the graphical view.

4

You should remove the first line (default) by clicking on the number at the f ar left of the table and click on the Remove button.

5

View the default couple inserted (1 cell for each link). We would like to change these numbers to link more cells. Manually change the numbers to 41 cells for the Main River and 2 cells for Tributary as shown on the image.

6

The couple link cells have been selected and are defined in a spreadsheet called “Couple.xls” under Model\COUPLE. For the Main River, copy the j,k data from the spreadsheet into the couple file.

7

For the Tributary, change the link cells manually. The values are also given in the “Couple.xls” file.

8

Go to the Standard/Structure Link Options page and change the Depth Adjustment to “Yes”, the Smoothing Factor to 0.4 and the Momentum Facto r as required. Refer to the User Manual for a description of the different options.

MIKE FLOOD Training


9

5.3

Create a Lateral Link for “Tributary” 1

Exercises

Save the couple file.

On the Link Definitions page, right-click on the graphical view and choose “Link river branch to MIKE 21”. This will open the Link river branch to MIKE 21 dialog. Select Lateral link Centre and connect the branch “Tributary” from chainage 3500m to chainage 10030m using one segment only. The Topo ID field should be filled in automatically once you have entered the river name.

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66

2

View the resulting lateral couple. A new line has been added in the dialog just above the layout and a green line in the layout indicates the location of the linkage. On the left side, the table defines the cells of the link. The cells have been chosen automatically but we will change them. Note the spatial difference between MIKE 21 (168*50=8400m) and MIKE 11 (100003500=6500m).

3

We would like to shorten the length of the link by removing the cells which are not above the channel in MIKE 21. The coupling cells have already been selected and are stored in the spreadsheet “couple.xls”. Manually change the number of cells to 130 and copy the values from the spreadsheet into the table to the left.

4

Under the Lateral Link Options page, check the lateral li nk options. We will leave the default values. Notice the Structure T ype, Method, Source, the Depth Tolerance… Refer to the User Manual for a description of the different options.

MIKE FLOOD Training


5

Exercises

Save the file.

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5.4

Blo ck Out River Cells in the Bathym etry File A residual channel remains in the MIKE 21 grid and this will result in duplicating the conveyance. This channel needs to be filled in the bathymetry to match the bank markers in MIKE 11.

68

1

Right-click in the layout and select the “Block Out River Cells” tool. The tool will make a selection file of the river cells based on the lateral couple. Fill in the River name, Topo ID and Chainages as shown on the image below.

2

Open “Grid50m_2.dfs2” and load the selection file you have just created in Tools > Load Selection. Note that the selection ma y need to be adjusted manually to match with the location of the channel.

MIKE FLOOD Training


Exercises

3

Delete the existing channel values and interpolate the new values by going to Tools > Interpolation and click OK (just leave the default parameters for interpolation).

4

Save the grid file without renaming it. The channel should be indiscernible from the floodplain now.

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5

5.5

Save the couple file and run the MIKE FLOOD simulation (choose Run > Start Simulation). Note that the run time is nearl y twice as long as when you run the standalone MIKE 21 model.

View the MIKE FLOOD 1 Results in Plot Com pos er Now that you have successfully run the first MIKE FLOOD simulation, you will look at the results using Plot Composer.

70

1

Open a new Plot Composer file from File > New > File > MIKE Zero > Plot Composer (.plc).

2

Load the result input file to “Mflood1.dfs2”. To do that, Go to Plot > Insert New Plot Object. Select the plot type Grid (dfs2). In the Plot Property dialog, load the result file.

3

Click the Items tab and select Water Depth and Velocity vectors to be plotted. Under Contours tab, un-tick the “Draw Isolines” and tick “Plot Color Legend”. You can explore the various tabs and change the properties of the plot as you like.

4

You can animate the plot by clicking on the Animate tab at the bottom left of the file. In this way, you can review the behaviour of the standard and lateral links.

5

Save the file as “Mflood1.plc” and close it.

MIKE FLOOD Training


5.6

Additional, if time permits…

Exercises

•

Save lateral inflow results in MIKE 11 HD file (Additional results).

•

Create seamless 1D-2D results in MIKE 11 HD file > Maps, select the h,p,q type.

•

Open the “MFLateral.xns11” generated in the folder where the MIKE 11 simulation file is located to compare M11 elevations, M21 elevations and lateral structure elevation. See manual for more details.

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MIKE FLOOD Training

Create Different MIKE FLOOD Models for Comparison

6

CREA TE DIFFERENT MIKE FLOOD MODEL S FOR COMPA RISON In this exercise you are going to set up two additional MIKE FLOOD models that include a new road embankment on the floodplain. The first setup will use an implicit structure to represent the road crossing while the second setup will use an explicit structure. Before running the MIKE FLOOD models, you need to change the MIKE 21 and MIKE 11 models to add the road embankment.

6.1

Create MIKE 21 Mod els for MIKE FLOOD

6.1.1


In this step you will modify the “Mflood1.m21” model to prepare “Mflood2.m21” model which will be used for assessing implicit couples/structures in the MIKE FLOOD Model 2.

6.1.2

1

Open the MIKE 21 flow model “Mflood1.m21” and rename it as “Mflood2.m21”.

2

Change the result file name to “Mflood2.dfs2.

3

Save the file. Note that all other parameters and files are unchanged.


In this step, you will modify the “Mflood2.m21” model to prepare “Mf lood3.m21” model which will be used for assessing explicit structures in MIKE FLOOD model 3.

Exercises

1

Open the MIKE 21 flow model “Mflood2.m21” and rename it as “Mflood3.m21”.

2

Under Bathymetry, use the grid “Grid50m_4.dfs2” as the bathymetry file. A dialog should be prompted asking if you would like to recalculate the boundaries. Click NO as some of the inflow boundaries will be assigned in MIKE 11 instead.

3

Under Results, change the result file name to “Mflood3.dfs2”.

4

Save the file and check that the simulation starts.

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6.2

MIKE FLOOD 2: Ass essm ent of Imp licit Coup les/Structures

6.2.1

Create MIKE FLOOD 2 Cou ple File

6.2.2

74

1

Save “Mflood1.couple” as “MFlood2.couple”.

2

Assign “Mflood2.m21” and “Mflood2.sim11” files.

3

Save the couple file.

Mod ify the MIKE 11 Mod el to Insert an H-Q-H Struc ture Bran ch

1

From the “Mflood2.couple” file, click “Edit MIKE 11 Input” to open the “Mflood2.sim11” file.

2

From the MIKE 11 simulation file, open the network file for edition.

3

Turn off the bathymetry in the background and turn on the image instead, by going to Layers > Properties.

4

Zoom into the bridge area on the graphical view.

5

To add the bridge structure, you need to add a new branch. Use the digitizing tools: Add new points and Define branch to create a new branch.

MIKE FLOOD Training


6

Exercises

Edit the branch name and chainages in the Tabular View as indicated on the images below. The name of the new branch is “HQH_Structure”, the TopoID is “Topo2006” and it goes from chainage 0 to chainage 100m.

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76

7

Save the network file.

8

Open the cross-section file from the simulation file. Find the chainage 11650m on the Main River. Copy the section (right-click option) to HQH_Structure 0 and 100m.

9

Close the cross-section file and reopen the network file. Verify that the 2 cross-sections have been added correctly.

MIKE FLOOD Training


10 We would like to insert a weir and a culvert on the HQH_Branch to represent the bridge. Click on one of the points of the branch to select it and then rightclick. In the menu that appears, choose Insert > Network > Weirs.

Exercises

77


11 In the network tabular view, enter the weir infor mation data, calculate the Q/h relationship and plot the weir. Chainage 50m Broad Crested Weir Level-Width table (enter the values indicated in th e image below).

12 In the same way as you have inserted a weir, you need to insert a culvert at chainage 50m. The upstream and downstream invert levels are -4.7m. The length of the culvert is 50m. The Manning‟s N roughness value is 0.02 and the number of culverts is 10. The culverts are rectangular with a width of 8m and a height of 6m. Plot the culvert and calculate the Q/h relationship.

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MIKE FLOOD Training


13 Click on “Grid Points” in the Overview tree and Generate the Grid Points. Observe the generated grid points for H-Q-H_Structure.

Exercises

79


14 To complete the updated MIKE 11 model, you now need to insert boundary conditions to the new branch. On the network graphical view, right-click at the upstream and downstream end of the branch and select Insert > Boundary > Hydrodynamic. The boundary file is open automat ically. Both boundaries are a constant water level of 0m.

15 Save all the files that you have just edited and check that the simulation runs.

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MIKE FLOOD Training


6.2.3

Exercises

Set up the Implic it Struc ture in MIKE FLOOD 2

1

Open the MIKE FLOOD file “Mflood2.couple”. Note the extra short branch in the layout (reload the simulation file if the branch does not appear in the window).

2

The new branch should be coupled to MIKE 21. Rightclick on the layout and select “Link branch to MIKE 21”. Connect the “HQH_Structure” branch using the Implicit Structure link. Note that both the upstream and downstream end of the branch are automatically coupled.

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82

3

Observe the added lines in the Couple Table and the changed colours in the graphical view.

4

Change the number of MIKE 21 cells that define the link to 7 for both couples.

5

The coupled cells have been defined in the spreadsheet “Couples.xls”. Open the spreadsheet and copy the 7 cells into the couple file for both links.

6

Under the Standard/Structure Link Options tab, change the Depth Adjustment to YES and the Exponential Smoothing Factor to 0.4m.

MIKE FLOOD Training


7

Exercises

Under the Definition Page, change the colour palette in the layout and load the existing palette “Topo.pfs”. Zoom into the view and look at the Implicit Links.

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6 .2 .4

Ad d Zero Flow Link s

A highway upgrade is proposed and you need to estimate the future road level above the flood level. You will use Zero Flow Links to insert a blockage on the floodplain so that the desired road level can be determined.

6.2.5

1

Manually insert two new links and change their type to XFLOW=0 and YFLOW=0.

2

The link cells are also defined in the “Couple.xls” spreadsheet. Open the spreadsheet and copy the reference cells into the couple file.

3

Zoom in the graphical view and view the zero flow links.

4

Save the MIKE FLOOD file and run the simulation. Note that the impact of Implicit Links on the run time is almost negligible.

5

Open the dfs2 result file and check the maximum water level upstream of the highway.

View and An alyse the Result s of MIKE FLOOD 2

Using MIKE VIEW:

84

1

Open MIKE VIEW from Start > Programs > MIKE BY DHI 2011> MIKE View > MIKE View.

2

Load the result file “mflood2.res11”.

MIKE FLOOD Training


3

Exercises

Review the water level and discharge at the bridge structure.

85


Using PLOT COMPOSER

86

1

In MIKE Zero, load the Plot Composer file “Exercise.plc” from the \Result directory.

2

Change the input file to “mflood2.dfs2” by right-clicking on the layout and selecting Properties.

3

You can animate the plot by going under the “Animate” tab and review the impact of the structure and the zero flow behaviour.

4

Rewind, save as “Mflood2.plc” and close the file.

MIKE FLOOD Training


6.3

MIKE FLOOD 3: Ass essm ent of Explicit Structures

6.3.1

Create MIKE FLOOD 3 Cou ple File

6.3.2

Exercises

1

Open “MFlood2.couple” and save it as “Mflood3.couple”.

2

Assign “Mflood3.m21” and leave “Mflood2.sim11” for the moment.

3

Open “Mflood2.sim11” and rename it as “Mflood3.sim11”. Change the result file name to “Mflood3.res11” and assign the new simula tion file to “Mflood3.couple” model.

Insert an H-H Struc ture Bran ch in MIKE 11

1

From the MIKE 11 simulation file “Mflood3.sim11”, open the network file for edition “mflood2.nwk11”. Change the network file name to “mflood3.nwk11” and assign it to the simulation file.

2

Zoom into the bridge location. We would like to digitize a new branch parallel to the HQH_branch you have created in the previous exercise. Use the digitizing tools to add a new branch as shown on the image below.

3

Edit the branch details in the network tabular view. The branch name is “HH_Conduit”, TopoID is “Topo2006” and the DxMax is 10m.

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4

88

Change the upstream and downstream points of the branch to User Defined at 0 and 50m.

MIKE FLOOD Training


Exercises

5

Go to Grid Points in the overview tree and Generate the Grid Points.

6

You need to insert new cross-sections to the HH_Conduit branch. From the graphical view, right-click on the upstream point of the branch and choose Insert > Network > Cross-sections.

7

The cross-section geometry is defined in a spreadsheet “Create Closed Sections 1.xls” under Model\MIKE11. Open the spreadsheet and copy the closed cross-section X, Z data into the cross-section file. The cross-section type is Closed Irregular. Note that the cross-section represents the 10 culverts 8*6m.

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8

Change the Settings and Processed Data of the cross -section as indicated in the image below. Recompute the levels with equidistant method.

9

Copy the cross-section to chainage 50m (right-click option). Save the crosssection file and close it.

10 You have now created a new branch and have added cross-sections. To complete the setup, you should insert water level boundary conditions to the branch at chainages 0 and 50m. Right-click on the network graphical view and choose Insert > Boundary > Hydrodynamic. In the boundary file, change the boundary to a constant water level of 0. Alter natively, you can go to Network > Auto Boundary (HD) Free Branch Ends. This will automatically add boundaries to the end of branches that do not have boundaries yet. Save the file as “mflood3.bnd11” and reload it into the simulation file.

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MIKE FLOOD Training


11 Go back to the network file and right-click on the branch to insert some local Manning‟s „n‟ roughness values of 0.02.

Exercises

91


12 Save and close the network, cross-section, boundary and HD files. Check that “Mflood3.sim11” runs.

6 .3 .3

92

D e f i n e E x p l i c i t L i n k s f o r H- H C o n d u i t i n M IK E F L O O D 3

1

Open “Mflood3.couple” and note the new structure branch at the bridge location.

2

Delete the Implicit Links 4 and 5. You will insert 2 new explicit standard links instead. Using the right-mouse click option, link the HH_Conduit upstream and downstream using explicit standard links.

3

Change the number of link cells to 7 for both links. The coupling cells are defined in the spreadsheet “Couples.xls” Copy the values into the couple file.

4

Under the Standard/Structure Link Options, change the Depth Adjustment to YES and set the Exponential Smoothing Factor to 0.4.

5

Change the colour palette of the graphical view (load the file “Topo.pfs”). Zoom in to view the links. The embankment separating the upstream and downstream links should be visible.

MIKE FLOOD Training


6

6.3.4

Exercises

Save the couple file and run the simulation.

View the Results of MIKE FLOOD 3

1

Create a new Plot Composer and save it as “Mflood3.plc”.

2

Load the input file “Mflood3.dfs2” and save the file. Change the properties of the plot to show water depth with velocity vectors.

3

Create an animation and review the flood behaviour at the bridge. Verif y that the river is blocked at the structure but that no flow passes through.

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MIKE FLOOD Training

Discussions

7

DISCUSSIONS

7.1

H-Q-H versu s H-H Struc tur e Metho d Conduit method or H-H method can be used for long culverts where inlet and outlet are not adjacent in the Grid.

Conduit method does not accurately account for structure head losses (contraction and expansion). Dominant parameter affecting head loss is Roughness in the Pipe/Culvert. No weir required as overtopping is done in MIKE21.

7.2

Exercises

Im plicit versus Explicit Structure Methods 1

Open MIKE View and load the MIKE 11 result file “Mflood2.res11”.

2

Plot the water level and discharge for HQH_Structure. Copy the water level values at HQH_Structure 0 and 100m into the spreadsheet called “Comparison.xls” under the \Result directory. Plot and copy the discharge results at HQH_Structure 50 into the same spreadsheet.

3

Load the “Mflood3.res11” results into MIKE View and plot the discharge and water level for HH_Conduit. In the same way, copy the results int o the spreadsheet for comparison between the 2 link methods.

4

View the graphs comparison in the spreadsheet.

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Comparison of Levels 3

2.5

l e v e L r e t a W

2

1.5

1 HQH_STRUCTURE 0.00 HQH_STRUCTURE 100.00

0.5

HH_CONDUIT 0.00 HH_CONDUIT 50.00

0 21-02-1992 00:00 21-02-1992 12:00

22-02-1992 00:00 22-02-1992 12:00

Date/Time

Comparison of Discharge 1600

1400

1200

e g r a h c s i D

1000

800

600

400 HQH_STRUCTURE 50.00

200

HH_CONDUIT 25.00

0 21-02-1992 00:00

21-02-1992 12:00

22-02-1992 00:00

22-02-1992 12:00

Date/Time

Structures are generally implemented as “Sub-Grid Scale” features. Therefore, IMPLICIT structures are recommended where the coupled cells (inlet and outlet) share a common face in MIKE21. •

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IMPLICIT formulation is preferred for Bridges.

MIKE FLOOD Training

Discussions

7.3

•

EXPLICIT H-Q-H structures are prone to instability at low flows and are not recommended.

•

CONDUIT H-H structures are very stable but do not accurately account for structure head losses (too hydraulically efficient).

Tips to Imp rove the Stability of the Link s The MIKE FLOOD User Manual contains a section on “Tips and Troubleshouting”. We really recommend that you read this section to try and improve the stability of your MIKE FLOOD model.

Exercises

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MIKE FLOOD Training

Result Extraction using Toolboxes

8

RESULT EXTRACTION USING TOOLB OXES You have now run different models and have produced 1D and 2D result files. Various tools exist to view, show and extract results from a MIKE FLOOD simulation. You have already used MIKE VIEW to look at MIKE 11 results, the Grid Editor to navigate through dfs2 results and Plot Composer. In this section, you will be introduced to some of t he conversion and extraction tools available in MIKE Zero to extract flood results, including MIKE Zero and MIKE 21 Toolboxes.

8.1 8.1

MIKE Zero Toolb ox A MIKE Zero Toolbox file has been prepared and 3 different tasks have been setup.

Exercises

1

Navigate to \Result directory directory and open “MZ_Toolbox.mzt”.

2

Extend the different sub-menus of the Tool List.

3

Under Extraction, open the setup “Extract Water Level”. This is an example for extraction of a time series from a 2D file. Review the settings (click Next >) for extraction. extraction. Note that you need to click on the “Execute” button to actually launch the extraction.

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4

Open the resulting time series.

5

Review the GIS > Grd2Mike > “Import ASCII” setup. It converts an ASCII file into a grid dfs2 file. Execute the file and open the resulting *.dfs2 file.

MIKE FLOOD Training


Exercises

6

Review the Statistics > TxStat > “Max Stats Surface” setup. This tool creates a maximum surface level dfs2 grid. Execute the fil e and open the resulting *.dfs2 file. This tool is very useful to create creat e maximum maps of your results (water level, depth, velocity…) and can be used for flood risk assessment, damage assessment…

7

Under Setup List, you can select the setups and click on “Run” to execute them.

8

Save and exit the MIKE Zero Toolbox.

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8.2

MIKE 21 Toolb ox In the same way as for the MIKE Zero Toolbox, a MIKE 21 Toolbox file has been prepared. In this example the Toolbox is used to extract the discharge between 2 points.

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1

Navigate to the \Result directory and open the file “M21_Toolbox.21t”.

2

Review the setup for Discharge extraction under Hydrodynamics > Discharge Calculation > Extract Discharge.

3

Execute the example setup.

4

View the result file. The result file contains instantaneous and cumulative discharge data; positive, negative and summed flow. By right-clicking on the graphical view, you can should the items you would like to display.

MIKE FLOOD Training


5

Exercises

Save and exit the MIKE 21 Toolbox setup.

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MIKE Flood River- Exercises

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