Abstract
Water resources in semi-arid regions are increasingly affected by climate variability, making hydrological modeling essential for assessing water availability and supporting watershed management. In this study, the Soil and Water Assessment Tool (SWAT) was applied to simulate the hydrological behavior of the Nfifikh watershed in Morocco using climate data from local meteorological stations complemented with gridded datasets, a 30 m digital elevation model, soil maps, and land-use data derived from satellite imagery. Observed streamflow at the watershed outlet was used for model calibration and validation following standard SWAT procedures. Model performance was evaluated using the Nash–Sutcliffe efficiency (NSE), coefficient of determination (R²), percent bias (PBIAS), and the RMSE– standard deviation ratio (RSR), showing very good agreement between simulated and observed daily flows. Results indicate that about two-thirds of annual precipitation is lost through evapotranspiration, while streamflow is generated through surface runoff, lateral flow, and shallow subsurface contributions. Spatial patterns highlight higher runoff and sediment production in steep upland areas and greater flow regulation downstream. The study provides useful insights for water resource management in semi-arid watersheds.