Modelling the hydrological processes of Koupendri catchment Northwest, Benin

摘要

This study calibrated and validated rainfall-runoff model (WaSiM) to aid decisions on sustainable management of scarce water resources in Koupendri catchment. The model was successfully calibrated (NSE = 0.61; R~(2)= 0.61, RMSE = 0.63) and validated (NSE = 0.68; R~(2)= 0.78; RMSE = 0.57) using optimised soil and land use parameters. Though the model underpredicted some of the peak flows, the overall calibration result could be adjudged satisfactory with a p-factor of 0.94 and an r-factor of 0.93 which were all within the acceptable range of uncertainty. Evapotranspiration and discharge constituted 98%-99% of the total water balance of the catchment while the change in soil moisture storage constituted only 2%. Surface runoff was the predominant streamflow component (86%-90%), suggesting infiltration excess overland flow as the main runoff generation mechanism for the catchment. The water balance reflected the hydro climatic conditions of the catchment with actual evapotranspiration ranging between 68% and 75% of the total annual rainfall.