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.

  1. Open Lesson 1, 2 or 3 completed project;

  2. Assign buildings;

  3. Assign walls;

  4. Save and export;

  5. 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

  1. 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.

  1. 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.

  1. Click the Evaluate Reduction Factors (ARF and WRF) icon.

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  1. Set up the parameters and click OK

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  1. Close OK the window.

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  1. 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.

  1. Clean the map. Uncheck Buildings (user layer) and ARF/WRF (schema layer). This will improve map loading speed.

  2. Click Boundary Condition Points in the User Layer group. Drag the file Walls.shp into the map space.

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  1. 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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  1. Click the Levee Elevation Tool from the FLO-2D Toolbar and click the Add Walls to User Levee Lines button.

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  1. Set the wall elevation and failure fields and click Add Walls to User Levee Lines.

  2. Check Levee Failure

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  1. 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.

  1. Click the Levee Elevation Tool from the FLO-2D Toolbar and click the Create Schematic Layers from User Levees button.

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  1. In this case, only levee lines are used. Uncheck elevation polygons if it is checked.

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  1. Duplicate levees were identified. Remove them by clicking Yes.

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  1. Once the process is complete, the following image will appear. Click OK to close it.

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  1. The FLO-2D walls are shown by the red cutoff marks. Visually inspecting them can help QC the data.

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  1. Turn on levee failure by clicking the prescribed failure checkbox on the Levee Failure Widget.

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Step 4: Export the project#

  1. 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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  1. Click Save.

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  1. This is a good point to save the project.

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  1. 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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  1. 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#

  1. Click the Run FLO-2D Icon.

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  1. 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.