The Compute Flow Paths command computes and traces the subbasin runoff flow path for a selected map location using the prepared terrain surface until the flow path reaches a sink or the edge of the processed DEM grid.
To use the Compute Flow Paths command, follow the steps below:
- From the Watershed ribbon menu, select Compute Flow Paths command.
- The Compute Flow Paths dialog box will be displayed.
- Define the name for the layer group in the Layer group name input field. This name identifies the layer group that will be created in the Map Data Layers panel that will contain the raindrop points, downstream overland flow paths, and main streams.
- The Delete previously computed overland flow paths checkbox can be checked to delete any previously computed runoff flow paths.
- Click the [Draw] button. The Computed Flow Paths dialog box will temporarily disappear, and a prompt will be displayed on the status bar directing the user to place the raindrop point(s).
- Click on the Map View to place the raindrop point(s). Notice that the number of raindrop points will be displayed on the status bar. Once finished, press the [Enter] key or right-click and select Done from the displayed context menu.
- The Compute Flow Paths dialog box will be redisplayed, and the total number of selected raindrop points will be displayed in the Raindrop points entry, as shown below.
- Click the [OK] button. Internally, the software will compute the downstream flow path from each raindrop point that will merge into a major stream. Once the process is complete, the overland flow path from each raindrop point will be displayed on the Map View as shown below.