Impact of climate change on variations in groundwater storage in the Saïss aquifer (Northern Morocco)

Abstract

This study examines the influence of rainfall intensity and drought regimes on groundwater levels in the Sais aquifer, located in a semi-arid region of Morocco. Using satellite-derived datasets and the Innovative Trend Analysis (ITA) method, the research analyses groundwater storage (GWS) trends, providing a robust approach to detect long-term changes compared to the Mann-Kendall test. The study employs Gravity Recovery and Climate Experiment (GRACE) gridded data to estimate groundwater fluctuations and assess time series trends in equivalent water thickness (EWT) and soil moisture. Results indicate a significant decline in groundwater levels, with 40% of monitoring sites showing a substantial downward trend and 60% experiencing pronounced declines. The estimated maximum groundwater storage loss is -0.244 cm/yr –1 . These findings highlight the adverse effects of overexploitation and inefficient irrigation. While the study’s reliance on satellite data provides valuable information, it may overlook localized variations, and GRACE data may be less accurate in areas with complex geological features. Despite these limitations, the research informs water management strategies to mitigate groundwater depletion. The novelty of this study lies in the use of the ITA technique to enhance trend detection accuracy and support sustainable groundwater management in vulnerable regions such as the Sais aquifer.