Climate drought and resilience of karst hydrosystems in semi-arid regions: Case of the Dir of Beni Mellal Atlas (Morocco)

This study examines climatic drought and the sustainability of karst springs in the Dir of Beni Mellal Atlas in Morocco, based on an analysis of precipitation, spring flows and hydrological breaks. Rainfall series were evaluated using the Standardised Precipitation Index (SPI-12), while multi-year variations in flow rates were analysed using baseflow and the CUSUM test. The results reveal high hydroclimatic variability marked by alternating dry and wet years, with a clear trend towards more frequent and intense dry spells since the 2000s. The CUSUM analysis shows a persistent cumulative deficit, reflecting progressive aridification and a decline in the resilience of karst systems. Karst springs show different responses depending on their location and hydrogeological structure, highlighting the importance of local characteristics in flow dynamics. This study highlights the complementarity of the SPI-12 and CUSUM indicators in assessing both the intensity of droughts and their accumulation, providing essential tools for the sustainable management of water resources in semi-arid areas of Morocco.