Abhatoo - Centre Nationale de Documentation

In the Moroccan Rif Mountains, hydric erosion leads to disastrous consequences for both the potential production of land and for water resources management and pollution in downstream area. The main objective of this study is to illustrate on the one hand, the determining of the change of space occupation, and on the other hand, the modeling of the erosion and deposition of soils. The satellite data analysis was used to identify the different classes of land cover (uncultivated lands and badlands, annual crops, arboriculture / Olive trees, reforestation and forest) in the watershed of Tarmast with an area of 69.58 km2, located in the North-East of Morocco. After mapping the spatial and temporal evolution of land use over a period of 15 years, soil losses were estimated by the RUSLE model (Revised Universal Soil Loss Equation). These spatial assessments of soil loss were then used in a sedimentation algorithm that models the transport of these soil losses through the river to the outfall. These spatial movements were then evaluated to estimate the net erosion and deposition for each homogeneous basic plot of the basin. This approach, based on remote sensing data and GIS tool allows a spatial monitoring of erosion and deposition of soil in the context of a marly watershed subject to a strong human pressure. It is also an effective way for the localization of sediment source areas and understanding of the interrelationships between the various parameters of the erosional processes in a Mediterranean environment.