Soil Erosion RiskMapping Using the Analytical Hierarchy Process (AHP) and Geographic Information System in the Tifnout-Askaoun Watershed, Southern Morocco

Abstract

Soil erosion, a natural process accelerated by humans, is one of the serious environmental problems facing farmers in the Tifnout Askaoun watershed in the Taroudant province of southern Morocco. The objective of this study is the qualitative mapping of areas at risk of water erosion in the Tifnout Askaoun watershed using the AHP method (Analytical Hierarchy Process), this method consists of a weighting of the factors adopted by a comparison. in pairs of factors that control erosion in this area. The main factors considered in this study are slope, drainage density, land use, soil erodibility and erosivity of precipitation. The erosion risk map obtained for the study area shows that the erosion phenomenon is threatening the Tifnout- Askaoun region in southern Morocco.The risk map has four classes ranging from low to very high erosion risk. It shows that more than 48% of the study area has a high to very high risk of erosion. The result shows that erosion is very strong in the northern part of the study area around the Ifni lake, while the risk becomes low in the south near the Aoulouz and Mokhtar Soussi dams. The study has shown that the phenomenon of water erosion is very intense in the areas located in the High Atlas and the areas located in the Anti Atlas presents a risk of erosion low to medium.