The objective of the present work is to contribute to the study and the numerical modelling of the hydric erosion in the plateau of Thies: through an application to the watershed of Kissane, according to the USLE (Universal Soil Loss Equation) model. The establishment of the USLE model requires data on the topography, the land use, the climatology and the pedology. One of the major difficulties in the elaboration of the model was the collection of relevant data. Indeed, the rural commune of Noto more exactly the village of Kissane is relatively little informated by the scientific bibliography. The geographical reference data on the topography, the precipitation, the land use either non-existent, or incomplete or obsolete on a small scale and the geo-referenced digital data are even rarer. The study, the combination of the data and in the modelling were operated in a Geographical Information System (GIS). Every factor is a digital estimation of a precise component that affects the gravity of the soil erosion in a given place. The realization of the land use map from the visual interpretation assisted by GIS, from the satellite imaging Landsat that covers the watershed of Kissane facilitated the extraction of the vegetation cover map, what allowed defining with more precision the most sensitive areas with erosion risk.