Optimizing soil conservation, water balance, and sediment yield in Northern Morocco: A detailed SWAT model analysis of the El-Makhazine basin

Morocco is grappling with a severe decline in surface water availability, significantly affecting dam reserves due to climate change and reduced rainfall. The El Makhazine dam in the north is essential, supplying ۷۰۰ Mm³ annually from its ۷۷۲.۹ Mm³ reservoir. It delivers ۱۸ Mm³ of drinking and industrial water annually and irrigates ۳۶,۰۰۰ hectares in the Loukkos area. This situation calls for urgent research and monitoring of water and sediment discharge to plan anti-erosion measures and ensure the sustainability of regional water resources. This study presents a novel application of the SWAT model to the basin, utilizing high-resolution data. The dataset includes climate, flow, and sediment concentration records from ۱۹۸۲ to ۲۰۲۰, topographic data, land use information from high-resolution Sentinel satellite images, and soil data from laboratory analyses. The SUFI۲ algorithm was used to simulate the basin's hydrological processes, while the SWAT-CUP program was employed for model calibration and validation over two periods (۱۹۸۲–۲۰۰۳ and ۲۰۰۴–۲۰۲۰). The model incorporated ۲۱ sensitivity parameters to control flows and sediments, with reliability assessed using three objective functions (NSE, PBIAS, and R²). The analysis revealed that evapotranspiration and surface runoff were the dominant processes in the basin's water yield and balance. Erosion rates and sediment loads ranged from ۷.۲۷ to ۸۶.۷۷ t/ha/yr, averaging ۳۱.۶۲ t/ha/yr. Sub-watersheds were prioritized based on erosion rates to target anti-erosion interventions effectively. The Best Management Practices simulation identified terracing as the most suitable practice for the region, reducing erosion by ۴۸.۷%. The model has demonstrated effectiveness in simulating watershed development and implementing practices to minimize dam siltation.

کلیدواژه ها:

Water availability ، Agriculture ، SWAT ، BMP ، Morocco