
AfrHySRTM is an adjusted elevation raster in which any depressions in the source Digital Elevation Model (DEM) have been eliminated (filled), but allowing for internal drainage since some landscapes contain natural depressions. These landscapes have their own internal drainage systems, which are not connected to adjacent watersheds. Null cells (drains) were placed in depressions exceeding a depth limit of 20 m and with no less than 1000 cells (pixels) during the DEM adjustment process.