I am perfoming a geospatial process whereby I want to use the flow accumulation (as an input for discharge proxy) in calculating stream power. I am using ArcGIS 10.2
So far I have: 1. Valley/channel slope and width 2. drainage area 3. Terrain analysis grids (flow acc, flow dir etc) 4. rainfall surface grid
I just wanted to know what is the formula behind weighting the flow accumulation with for example, if facc is calculating the number of upstream cells accumulating in that point, when you weight it by rainfall (in mm), what does that mean? Sum? Multiplication of the two layers? I managed to do this step however, the values I got on the highest flow accumulation line is the same throughout the course of the river and that looks incorrect.