Is watercourse alignment data necessary to interpolate a DEM?
No, it is not required but it helps. You may find that DEMs interpolated without using watercourse alignment data do not represent the catchment perfectly, particularly where contour data is limited or large amounts of terrain fall within contour increments. It can be helpful in the absence of watercourse alignment data to manually draw the expected main stream alignment and use it as the watercourse layer to produce a more hydrologically accurate DEM. This can be done by Heads Up Digitising (HUD) in CatchmentSIM or importing the new layer from an external GIS or drafting application.
