Lesson 4 – Buildings, Walls and Wall Failure#
Overview#
Lesson 4 will outline the process of setting up buildings and walls and defining wall failure parameters in a FLO-2D project using the Plugin for QGIS. Apply these instructions after Lesson 1, 2 or 3 are completed.
This video shows the full process of this tutorial.
Required Data#
The lesson makes use of buildings and walls shapefiles.
File |
Content |
Location |
Buildings.shp |
Building shapefile |
QGIS Lesson 4 |
Walls.shp |
Walls shapefile |
Project Location C:\Users\Public\Documents\FLO-2D Pro Documentation\Example Projects\QGIS Tutorials
Check these folders to ensure the data is available before starting the lesson.
Step-by-Step Procedure#
To setup a FLO-2D flood simulation use these steps.
Open Lesson 1, 2 or 3 completed project;
Assign buildings;
Assign walls;
Save and export;
Run the simulation.
Step 1: Open project QGIS and load the FLO-2D Plugin data#
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Search the start menu and run the “QGIS Desktop” program.
QGIS Lesson 1, 2 or 3 can be used to for this project. Click Open Project and navigate to Example Projects. If QGIS Lesson 1, 2 or 3 are complete, choose any of these files to continue with Lesson 4. This tutorial will continue from Lesson 3.
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C:\Users\Public\Documents\FLO-2D PRO Documentation\Example Projects\QGIS Tutorials\QGIS Lesson 1\QGIS Lesson 1.qgz
Click Yes in the FLO-2D window to Load the model.
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Step 2: Assign buildings#
Note
The video at the top of this tutorial shows how to remove, add or modify the building polygons.
Drag the Buildings.shp shapefile onto the map space.
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The Buildings.shp shapefile needs 3 Attributes.
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These fields represent switches to set the calculation control for each building.
Collapse = 0 will ignore building collapse settings.
Collapse = 1 will apply the control for building collapse. If building collapse is needed, look in the Data Input manual for an extra data file.
ARF = 0 will ignore the ARF calculation.
ARF = 1 will calculate the ARF calculation.
WRF = 0 will ignore the spatially variable WRF but apply a T line to any totally blocked cell.
WRF = 1 will calculate the spatially variable WRF and apply a T line to any totally blocked cell.
Click the Evaluate Reduction Factors (ARF and WRF) icon.
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Set up the parameters and click OK
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Close OK the window.
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The new layers show ARFs and Blocked Areas Polygons.
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Step 3: Assign walls#
Note
The video at the top of this tutorial shows how to add, delete, or modify wall polylines.
Clean the map. Uncheck Buildings (user layer) and ARF/WRF (schema layer). This will improve map loading speed.
Click Boundary Condition Points in the User Layer group. Drag the file Walls.shp into the map space.
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If the walls are hard to see, make an adjustment to the symbology properties. Double click Walls layer to open the properties window.
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Click the Levee Elevation Tool from the FLO-2D Toolbar and click the Add Walls to User Levee Lines button.
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Set the wall elevation and failure fields and click Add Walls to User Levee Lines.
Check Levee Failure
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The levees were added to the user layer. Click OK.
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Note
If an error message was displayed, move the Walls Layer to the User Layer Group.
Click the Levee Elevation Tool from the FLO-2D Toolbar and click the Create Schematic Layers from User Levees button.
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In this case, only levee lines are used. Uncheck elevation polygons if it is checked.
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Duplicate levees were identified. Remove them by clicking Yes.
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Once the process is complete, the following image will appear. Click OK to close it.
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The FLO-2D walls are shown by the red cutoff marks. Visually inspecting them can help QC the data.
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Turn on levee failure by clicking the prescribed failure checkbox on the Levee Failure Widget.
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Step 4: Export the project#
Click the Set Control Parameters icon and enter the data in the FLO-2D Toolbar. The following dialog will be displayed, make sure the Area Reduction Factors and Levees component switches are selected.
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Click Save.
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This is a good point to save the project.
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Export the data files to the project folder in QGIS Lesson 4.
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C:\Users\Public\Documents\FLO-2D PRO Documentation\Example Projects\QGIS Tutorials\QGIS Lesson 4\QGIS Lesson 4 Export
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Complete the export by saving the swmm.inp file and clicking through all the remaining messages.
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Step 5: Run the simulation#
Click the Run FLO-2D Icon.
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Set the Project path and the FLO-2D Engine Path and click OK to start the simulation.
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Summary#
This is the completion of a tutorial for adding buildings and walls to a model that is ready to run. This tutorial can be applied to any project once the grid and elevation is assigned.