MEASUREMENT AND MODELLING OF SOIL EROSION USING THE IntErO AND GAVRILOVIC MODEL (EPM) BY USING GIS WITHIN ASSIF MELLOUL BASIN, CENTRAL HIGH ATLAS, MOROCCO

Water erosion is a major environmental threat that contributes to soil degradation, reduced land productivity, and damage to infrastructure, particularly in mountainous and semi-arid areas.The High Atlas of Morocco represents a critical erosion hotspot, where steep slopes, heterogeneous lithology, and complex hydrological networks amplify erosion susceptibility.Despite its vulnerability, no spatially explicit erosion modelling has previously been applied to the Assif Melloul basin, making this study a novel contribution to erosion assessment in the region.This research presents the first integrated application of the IntErO and Erosion Potential Method (EPM) by using GIS techniques in this basin to quantify soil loss, identify the driving factors, and generate erosion severity maps.The methodology combines morphometric analysis, thematic factor integration (e.g., slope, rainfall erosivity, soil sensitivity, vegetation cover), and field validation.The IntErO and EPM models generated spatial maps of erosion intensity (W), supported by coefficients such as erosion dynamics (), threshold index (Z), and vegetation protection (Xa).Results show that nearly 90% of the basin is affected by severe to excessive erosion, with the "very severe" class covering 38%.Production of erosion material exceeds 16,000 m/km/year, predominantly in high-altitude, poorly vegetated zones.Furthermore, NDVI-based land cover