Evaluation of Swat Performance on a Mountainous Watershed in Tropical Africa

Abstract

Soil and water assessment Tool is used to model the hydrology of a mountainous catchment in tropical Africa. Land cover and soil characteristics for the catchment were used to determine initial model parameters that were later adjusted during a calibration process. The model was calibrated and validated against measured stream flow. Although the model performed satisfactorily for simulating monthly river flows based on SWAT model calibration guidelines, it fell short of capturing daily peak flows. Average error on prediction of daily peak flows was-19.8%, while the median error was 10.8%.Overall, the average simulated daily peak flow was 2.6 cms less than the corresponding observed daily peak flow, indicating a model tendency to under predict the magnitude of peak events. The inability of the model to capture peak flows was found to be the main limiting factor for its performance.