I think there must be a straight forward answer to this but I haven't managed yet:
I have two shapefiles for the same watershed they are both divided into different areas with different erosion factors. I am trying to get a new shapefile with, say, the sum of both factors (a column in each file). The problem is that a polygon from one file isn't necessarily covering the same area as a polygon from the other file.
What would be the best approach to this task?