Measuring land losses caused by water erosion using the SWAT model in the Ourika watershed in the High Atlas of Morocco

In Morocco, the phenomena of water erosion cause significant economic losses mainly linked to silting up dams, degradation equipment and socio-economic infrastructures, loss soil productivity insecurity population. The SWAT (Soil Water Assessment Tool) model was used estimate quantities sediments generated by various erosive processes at level Ourika watershed. modeling, which is done with daily time steps, as basic data; a Digital Elevation Model GDEM-ASTER (Global Elevation-Advanced Space borne Thermal Emission Reflection Radiometer) 30 m resolution, land cover map developed from Landsat 8 OLI (Operational Land Imager) satellite image 2017 resolution published FAO (Harmonized World Soil Database). Also, meteorological data Tensift Basin Agency over period 1992 2001 were used. results obtained showed that due in watershed reached an average 9.18 t.ha-1.year-1. calibrated validated using SWAT-CUP (SWAT Calibration Uncertainty Procedures) software SUFI-2 (Sequential Fitting) after several simulations iterations determination coefficient R2 0.76 obtained.