Role of spatial aggregation over runoff calculations on southeast France catchments

The paper investigates the catchment area extension calculations as a function of the adopted spatial resolution and the effect of these spatial resolutions on the runoff calculations, for a number of catchments. Calculations were done with hypothetical and constant amounts of precipitation over space. Adopted grid size varied from 3000 to 2 m. Area estimate errors were computed in respect to 2 m grid resolution and the SCS method used for excess precipitation calculations. Results have shown that 75% of the catchments have errors of <15% of its area at any resolution and that the surface estimation errors are < ±1% for a 200 m spatial resolution. For any catchment effective precipitation presented, small variations occurred when 300 m spatial resolution was used and at 100 m spatial resolution almost no variations were observed.