Calibration and Validation of SWAT Model by Using Hydrological Remote Sensing Observables in the Lake Chad Basin

Model calibration and validation are challenging in poorly gauged basins. We developed applied a new approach to calibrate hydrological models using distributed geospatial remote sensing data. The Soil Water Assessment Tool (SWAT) model was calibrated only twelve months of data on actual evapotranspiration (ETa) geospatially the 37 sub-basins Lake Chad Basin Africa. Global sensitivity analysis conducted identify influential parameters by applying Sequential Uncertainty Fitting Algorithm–version 2 (SUFI-2), included SWAT-Calibration Program (SWAT-CUP). This procedure is designed deal with spatially variable estimates either multiplicative or additive corrections applicable entire domain, which limits number unknowns while preserving spatial variability. led us fifteen parameters, were selected for calibration. optimized gave best performance basis high Nash–Sutcliffe Efficiency (NSE), Kling–Gupta (KGE), determination coefficient (R2). Four sets ETa products calibration, i.e., ETMonitor, GLEAM, SSEBop, WaPOR. Overall, limited period time robust very good performance, R2 > 0.9, NSE 0.8, KGE 0.75 SWAT vs. ETMonitor GLEAM ETa. finally adopted further applications. then validated during 2010–2015 against total water storage change (TWSC) acceptable = 0.57 0.55, soil moisture greater than 0.85.