Quantitative assessment of groundwater recharge decline in the Maamora aquifer, Morocco, under RCP4.5 and RCP8.5 using CORDEX climate projections

Morocco is dominated by an arid and semi-arid climate, with a limited area in the north exhibiting a Mediterranean climate. It has been shown in recent years that the impact of Climate Change (CC) has increasingly changed hydrological patterns, which has led to irregular precipitation regimes and rising temperatures. These shifts have intensified extreme events, such as droughts, thereby raising significant concerns regarding the sustainability and consistency of future water resources management. This study evaluates future impact of CC in the Maamora region by projecting temperature and precipitation trends under two Representative Concentration Pathway (RCP) scenarios. High-resolution climate data were obtained from the CORDEX (Coordinated Regional Downscaling Experiment) initiative. In particular, downscaled data from the EC-EARTH climate model were selected for the period 2025-2100. This model has been proven for its robustness and accuracy in simulating long-term climate trends in North Africa. Aquifer recharge was estimated based on the projected climate variables. Results indicate a declining trend in precipitation and an increase in temperature under both RCP4.5 and RCP8.5 scenarios, with a more pronounced reduction in precipitation under RCP8.5. Correspondingly, aquifer recharge is projected to decrease in both scenarios, with greater and more extreme fluctuations under RCP8.5.