The Hassan II dam, located in the eastern part of Morocco in the Upper Moulouya, serves as the primary water supply system for drinking water and irrigation of agricultural lands in the surrounding areas. Yet, considering the imminent challenge posed by climate change, this hydraulic infrastructure faces environmental sustainability challenge due to sedimentation caused by soil degradation in its upstream entering. Therefore, monitoring soil loss, identifying the sediment origins with the vulnerable areas under high risk of erosion have become critical for decision-makers to choose wisely effective conservation strategies that promote sustainable land management, water mitigation and provide protection to Hassan II dam from siltation and improve its lifespan. This study evaluates the spatial distribution of soil loss and sediment yield in the Upper Moulouya watershed using the Revised Universal Soil Loss Equation (RUSLE) combined with a geographic information system (GIS). By integrating the main factors controlling soil erosion, such as topography, vegetation cover, soil proprieties, and climate, the maps of soil erosion and sediment yield were achieved. The results showed that the mean annual soil loss was 10.82 t/ha/y with an annual erosion amount of 3.46 million tons, highlighting a hazardous rate of erosion potential that could rapidly silt the Hassan II dam. In total, 45.14% of the watershed surface experienced soil erosion less than 5 t/ha/y, while 21.38% endured high to severe risk of soil loss. Areas characterized by steeper slopes and limited vegetation cover experienced elevated levels of soil degradation. The sediment yield using the delivery ratio was identified to be 5.56 t/ha/y, which was lower than the bathymetric value of 12.32 t/ha/y. The difference of 7 t/ha/y between these values may be attributed to the fact that a part of these sediments was not retained in the Upper basin but instead continued downstream to the hydraulic infrastructure of the Hassan II dam. The results undeniably assisted in pinpointing key areas where conservation practices should be implemented, ensuring the sustainability of the Hassan II dam situated downstream in the Upper Moulouya catchment.

哈桑二世大坝位于摩洛哥东部穆卢亚上游，是周边地区饮用水和农田灌溉的主要供水系统。然而，考虑到气候变化带来的迫在眉睫的挑战，由于上游入口土壤退化造成沉积，该水利基础设施面临环境可持续性挑战。因此，监测水土流失、确定高风险侵蚀脆弱地区的沉积物来源已成为决策者选择明智有效的保护战略的关键，以促进可持续土地管理、减少水资源并为哈桑二世大坝提供保护，使其免受淤积和侵蚀。提高其使用寿命。本研究利用修订后的通用土壤流失方程 (RUSLE) 与地理信息系统 (GIS) 相结合，评估了穆卢亚上游流域的土壤流失和产沙量的空间分布。综合地形、植被覆盖、土壤性质、气候等控制土壤侵蚀的主要因素，绘制出土壤侵蚀产沙图。结果显示，年平均土壤流失量为10.82吨/公顷，年侵蚀量为346万吨，突显了潜在的侵蚀危险率，可能会迅速淤塞哈桑二世大坝。共有45.14%的流域表面水土流失小于5吨/公顷/年，21.38%的流域表面存在高至重度水土流失风险。坡度较陡、植被覆盖有限的地区土壤退化程度较高。使用输送比确定的沉积物产量为 5.56 吨/公顷/年，低于测深值 12.32 吨/公顷/年。这些值之间 7 吨/公顷/年的差异可能是由于这些沉积物的一部分没有保留在上游流域，而是继续下游至哈桑二世大坝的水利基础设施。无可否认，研究结果有助于确定应实施保护措施的关键领域，确保位于穆卢亚上游流域下游的哈桑二世大坝的可持续性。