I am working through the "Calculate Area and Volume" exercise in the web course, Creating 3D Data Using ArcGIS 10. I understand how 3D analyst works. However, the exercise comes with a "basin raster" that "represents the basin that is upstream of the dam". The exercise does not give a clue as to how to make this raster. It is draped over the elevation layer, but how is its boundary established?
Thanks
Jim
