In the field of the water resources, hydrologic models have been used to assess water quality performance of complex watersheds and river basins. Hydrologic models can provide essential information for making decision...In the field of the water resources, hydrologic models have been used to assess water quality performance of complex watersheds and river basins. Hydrologic models can provide essential information for making decisions on sustainable management system of water resources within watersheds. The main objective of this study was to validate the performance of the Soil and Water Assessment Tool （SWAT） and the feasibility of using this model as a simulator of runoff at a catchment scale in semi-arid area in Northwestern Tunisia. Calibration and validation of the model output were performed by comparing predicted runoff with corresponding measurements from the Sarrath outlet for the periods 1990-1995 for calibration and 2000-2005 for validation. The time series for the years 1996-1999 showed discrepancies between the measured rainfall and the observed runoff indicating errors due to either the observations or to a dysfunction in the equipments. Sensitivity analysis shows that sensitive parameters for the simulation of discharge include curve number, soil evaporation compensation factor, depth of water in shallow aquifer and slope of subbasin. Statistical comparisons between monthly simulated results and observed data for the calibration period gave a reasonable agreement with a coefficient of determination （R2） greater than 0.75 and Nash-Sutcliffe Coefficient （NSE） equal to 0.72. These values were respectively 0.70 and 0.64 for validation period. Overall, the SWAT model has the capability to predict runoff within a complex semi-arid catchment.展开更多
文摘In the field of the water resources, hydrologic models have been used to assess water quality performance of complex watersheds and river basins. Hydrologic models can provide essential information for making decisions on sustainable management system of water resources within watersheds. The main objective of this study was to validate the performance of the Soil and Water Assessment Tool （SWAT） and the feasibility of using this model as a simulator of runoff at a catchment scale in semi-arid area in Northwestern Tunisia. Calibration and validation of the model output were performed by comparing predicted runoff with corresponding measurements from the Sarrath outlet for the periods 1990-1995 for calibration and 2000-2005 for validation. The time series for the years 1996-1999 showed discrepancies between the measured rainfall and the observed runoff indicating errors due to either the observations or to a dysfunction in the equipments. Sensitivity analysis shows that sensitive parameters for the simulation of discharge include curve number, soil evaporation compensation factor, depth of water in shallow aquifer and slope of subbasin. Statistical comparisons between monthly simulated results and observed data for the calibration period gave a reasonable agreement with a coefficient of determination （R2） greater than 0.75 and Nash-Sutcliffe Coefficient （NSE） equal to 0.72. These values were respectively 0.70 and 0.64 for validation period. Overall, the SWAT model has the capability to predict runoff within a complex semi-arid catchment.
