Abstract
This study aimed to evaluate the extent and severity of water erosion in the Toudgha river catchment in the Central High Atlas of Morocco using two different erosion models, the Erosion Potential Model (EPM) and the Priority Actions Programme/Regional Activity Centre (PAP/RAC) model. From the modeling results, the catchment was affected by varying degrees of erosion, ranging from "very slight" to "excessive", with different locations identified under each model. The very high erosion areas were located in the extreme northwest of the catchment area for both of the applied models, covering 9.65% (according to PAP/RAC) and 8.56% (EPM) of the total area primarily driven by factors such as intense rainfall events, limited vegetation cover, high soil erodibility due to low organic matter content and coarser soil texture, and human activities such as overgrazing and land use changes, which exacerbate the effects of these natural factors on water erosion in these semi-arid areas. The study's findings suggest that erosion is a significant concern in these environmental areas and provide valuable information for designing effective erosion control measures and guiding soil and environmental management practices. Both models effectively simulated the erosion phenomenon and provided useful tools for soil and environmental management. The EPM model can be used to design effective erosion control measures, while the PAP/RAC model can be used to develop a comprehensive strategy for the sustainable management of the catchment area. These results have implications for the implementation of effective erosion control measures in mountainous watersheds and highlight the need for further research in this area.