Modélisation de l'érosion hydrique et des facteurs causaux, Cas de l'oued Sahla, Rif Central, Maroc

This work is the result of an assessment of erosion level and causal factors of soil erosion risk in the Sahla catchment (Taounate region) by using the PAP/RAC model. This watershed is an agricultural vocation and soil erosion risk is a major constraint to its development. Examinations based on replacing the PAP/RAC parameters in its classic version by others borrowed from other models that explain more erosion risks, were made to determine the parameter which controls more soil erosion. The study of erodibility in the PAP/RAC model is based on the slope and lithologic friability. In this study, these two parameters have been replaced respectively by the topographic factor WISCHMEIER & SMITH (1978) and soil types. These two parameters were classified as directed by the PAP/RAC and had been incorporated into the model. The main causal factors of soil erosion risk, their interactions, and their distributions had been defined through correlations analysis. These last had detected the factors and the part requiring fast and effective intervention to counteract the effect of soil erosion. These results can be an available document as support in projects of planning and erosion control management.