WMS:GSSHA Corrected Overland Flow Workflow

To correct overland flow in a GSSHA model, do the following:

1. Visualize the digital dam.
Turn on the Digital Dams option on the 2D Grid tab of the Display Options dialog. Alternatively, select Blocked under the Cells option on the 2D Grid tab of the display options.

2. Modify the digital dam.

Run the CleanDam algorithm in the GSSHA menu to slightly alter the cell elevations to fix the digital dam. A polygon can be designated as a Depression Mask polygon by using the Polygon Attributes dialog. This will prevent the elevations of cells within the polygon from being affected by the CleanDam program. Manually adjust the cell elevations. Changing the grid resolution can sometimes help eliminate digital dams.

3. Visualize Overland Flow results.
Run the simulation. Turn on contours. Open the properties of the cleaned GSSHA file in the Project Explorer to see if any elevations still need to be adjusted. Adjust the elevations and re-run the simulation.