Assessing soil loss patterns within the Srou River Basin, Atlas Mountains (Morocco)
摘要
The Mediterranean region, renowned for its diverse ecosystems and varied landscapes, is experiencing increasing soil erosion, particularly in areas with changing vegetation cover. This study examines how land-cover dynamics influence soil erosion intensity in the Srou River Basin in the southwestern Middle Atlas of Morocco. The adopted methodology employs the Revised Universal Soil Loss Equation (RUSLE), which assesses factors such as rainfall erosivity, soil erodibility, slope characteristics, land cover, and conservation practices. The basin is primarily composed of dolomitic limestones, doleritic basalts, red clays, and Paleozoic shales, sandstones, and quartzites, and receives an average annual rainfall (1980–2022) of approximately 522 mm. The soil loss analysis identified several erosion categories, with soil loss values expressed in tons per hectare per year (t ha−1 yr−1). The estimated maximum soil loss within the basin exceeds 114 t ha−1 yr−1. The high rate of erosion is observed within the badlands areas in the middle of the basin. Various factors explain the variability in soil loss. Lithology plays an important role in runoff generation and contributes to soil erosion. Moreover, soils on marls and red clays are more vulnerable to erosion and are considered the most erodible areas in the study site. Vegetation cover indicates the high intensity of erosion, ranging from open to dense forest. Areas with dense forest (e.g., Green Oak, Juniper, Cedar…) exhibit low rates of soil loss, while zones with open forest (e.g., matorral forest, shrubs…) indicate a high rate of soil erosion. Rainfall seasonality clearly influences sediment transport and increases soil loss during storm events. Consequently, our study provides important insights into the sustainable use of land. It can contribute to the effective conservation of soil in mountainous areas such as the Middle Atlas of Morocco.