Percent Impervious, can be extracted for Cross Sections and 2D Flow Areas from a specified Land Cover layer. The Percent Impervious group layer will profile sub-layers for Calibration Regions and the result Final Values raster used in the model. Base Percent Impervious Values and overrides should be specified on the Land Cover layer. Once finalized, the Land Cover layer is then associated with the Geometry. During model analysis and refinement, the Calibration Regions polygon layer can be used to modify specific areas in the model.
To add a Calibration Region, start Editing. Create the polygon of interest and provide an unique name (all calibration regions are unique).
The new region will be added to the Land Cover Parameters table and allow the user to specify how to treat the region. Entering a value for the new region ("Polygon 1") will take precedence over those values in the Land Cover dataset ("Percent Impervious" values). Base Override values may also be specified to globally replace values, while the Calibration Region only affects the area within the Region.
