Evaluating soil loss and sediment yield for sustainable management of the Hassan II dam within Morocco’s Upper Moulouya watershed using RUSLE model and GIS

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