I have tested the InVEST SDR model in many watersheds of the Ethiopian Highlands and the performance of the model is very good for smaller watersheds. In the larger watersheds, the model overestimates soil loss. I have checked why the model does this and finally, I understand that it is from the LS equation.
Therefore, my recommendation to the developer of the model is the following:
- To allow the user to use its own LS factor like what can we do for the R and K factors
- Otherwise, include at least four or three common LS factor equations. So that the user can choose the best one.