The impact area (formerly known as damage reaches in HEC-FDA Version 1) is the smallest geographical unit at which we calculate risk (at which we apply the risk equation).
To import impact area set, from the Study Tree, right-click on Impact Area Set and select the import command.
From the Import Impact Area Set dialog, enter a name and description. Click the browser ellipse button to navigate to the appropriate file and click Open to set the shapefile path. Then select the unique impact area name (a field of the attribute table). Click OK to import the dataset.
Only one set of impact areas may be imported into an HEC-FDA file. This means that all impact areas must be included in one polygon shapefile to be used in a study that contains a field for a unique impact area ID.
