Assessment of Water Erosion Risks in the Oued Beht Watershed, Upstream of the Ouljet Essoltane Dam: A Combined Approach Using the Erosion Potential Model and PAP/CAR Standards

Abstract

Morocco's semi-arid environment, diverse geography, and extensive agricultural practices present serious water erosion problems for the Ouljet Esoultan watershed, a sub-basin of the Beht River. This study evaluates the qualitative and quantitative risks of water erosion using the Erosion Potential Model and the PAP/CAR standards. According to the PAP/CAR technique, high erosion classes make up 11% of the watershed, whereas low to very low erosion classes predominate, making up roughly 73%. The predominant erosion forms (sheet, rill, and gully erosion) collectively affect 76% of the area within the Ouljet Esoultan watershed. The EPM results indicate that medium to high erosion levels, primarily in the central and upper zones, covers 76% of the watershed. The annual soil loss in an average year was calculated as 1600 m3 /km²/year. This analysis underscores the urgent need for targeted soil conservation practices tailored to the specific conditions of each erosion class within the watershed, to ensure sustainable land systems in semi-arid areas and to reduce the risk of erosion in highly vulnerable regions.