Understanding the Groundwater Recharge Processes in the Moroccan Middle Atlas Using Water Isotopes ( \(\updelta \) 18O and \(\updelta \) 2H)

Morocco is characterized by a semi-arid to arid climate, except for a humid zone in the North. This climatic restraint, accentuated by climate change and the high demand for water resources, requires the application of new approaches to complement conventional hydrological methods that will help to improve water assessment and management strategies. Among these approaches, stable isotopes allow to understand the different processes involving groundwater or water resources in general. The Atlas Mountains are an important supply of surface and groundwater, with a significant portion stemming from the snow cover. Hence, this work seeks to quantify the snowmelt contribution to surface water and groundwater recharge in the High Oum Er-rbiaa (HOER) through the Middle Atlas Mountains, by adopting the approach of stable isotopes. The methodology consisted in collecting surface, groundwater, precipitation and snow cover during an entire hydrological year. Preliminary findings are unveiled, as follows: the extensive isotope values of precipitation compared to surface and groundwater were revealed to be an indicator of a variety of recharge conditions, such as high altitude and temperature. Further assessment of the recharge altitude following an altitudinal gradient of − 0.27%/100 m indicated a recharge altitude between 1600 and 3200 (m asl).