Convert to Shapefile - Converts the raster stream and basin representations to line and polygon shapes. Compute Parameters - Computes areas, slopes, runoff distances, and other basin properties and stores as attributes in the corresponding shapefiles. Other attributes for the different shapes will likely be added as the project progresses. It is a single-event, lumped parameter model, but includes several different options for modeling rainfall, losses, unit hydrographs, and stream routing. The HEC-1 interface in WMS makes it simple to enter and manage input data and process results.
All input is managed through a single dialog as shown in the figure below.
HEC-1 style inputs for selected basins and outlets is shown and a model checker can be run to verify that data is consistent and properly defined prior to actually running the model. Watershed data such as area, slope, and median elevation are the primary variables used by most of the regression equations. The dialog below illustrates how the interface in WMS is used to compute peak flows and runoff hydrographs with the regional regression equations. The Rational Method is one of the simplest and best known methods routinely applied in urban hydrology. Routing lag times and level-pool routing through detention ponds can also be specified in order to develop runoff from a large catchment which has been subdivided into several smaller basins.