Beht Watershed (Morocco) Rainfall-Runoff Simulation with the HEC-HMS Hydrological Model

This research aimed to prepare for spatial hydrological modeling using the Hydrologic Modeling System (HEC-HMS) by integrating different spatial technologies to study the Beht catchment area, which covers 4560 km 2 and also has a perimeter of 414 km.Firstly, the approach was to extract automatically the sub-basins and the drainage network.Then, these data were edited using the HEC-GEO-HMS extension, whereas the land use and land cover data were prepared for the generation of a Curve Number (CN) map of Beht watershed; lastly, the basin model was imported into the Hydrologic Modeling System (HEC-HMS) to simulate the surface runoff.The findings indicated a good match between the calculated and measured values and revealed also that the model is valid, good and performed well in terms of assessment criterion, with average values of Relative Error in peak: REP = 9.6%, Relative Error in volume: REV = 1.69%,Nash-Sutcliffe Efficiency: NSE = 0.63, coefficient of determination: R2 = 0.870, and Ratio of standard deviation of observations to root mean square error: RSR = 0.36.