Analysis of the hydro-sedimentary functioning of a watershed of the Western Rif of Morocco using the SWAT model: Case of the Tleta watershed
SWAT Model (Soil and Water Assessment Tool) is a tool for simulating flows in the landscape, usefulfor guiding management and ground works within catchment areas. Accordingly, this model was tested to reproduce, on a daily times pan, water and sediment flows arriving to Ibn Batouta reservoir over the period 1980-2010. Various climatic (precipitation and temperature), morphologic (MNT) and thematic data (land use and pedology) were used for feeding the model. The measurements acquired at Ibn Batouta reservoir during the periods 1980-1982, 1983-1996 and 1997-2010 were used respectively for initialization, calibration and validation after running the sensitivity analysis to determine the most significant parameters. The performances indices of R², NSE and PBIAS were adopted to assess and control the quality of predictions of the monthly flows of water and sediments. The performance of prediction of monthly water flows is very high with R² (0.95; 0.90), NSE (0.94; 0.89) and PBIAS (-6; 2) respectively for both periods of calibration and validation. Meanwhile the performance of predictions of the monthly solid transport is very satisfactory with R² (0.83; 0.64), NSE (0.82; 0.61) and PBIAS (17; -6) respectively. Finally, SWAT model allows to properly reproducing monthly water and sediment flows within the Tleta catchment area and testing scenarios of management and ground works to be considered.
Key words: SWAT, hydrological modeling, water erosion, Western Rif, Morocco