Determination of recharge modes of aquifers by use of chemical and isotopic tracers. Case study of the contact zone between the Western High-Atlas Chain and Souss Plain (SW Morocco)
Determination of the origin of recharge of the unconfined aquifer in the right side of the Souss wadi between Agadir and Taroudant (South-west of Morocco) was based on the use of hydrochemical and isotopic analysis of groundwater, surface water and springs of the contact zone between the High-Atlas Chain and the Souss plain. The correspondence in the space evolution of the various chemical elements of evaporitic origin (SO42-, Cl-, Sr2+) in groundwater, piedmont springs, and surface water reveals the existence of recharge water from the adjacent High-Atlas Chain. The various recharge modes of the different aquifers (High Atlas and Souss plain) determined by isotopic analysis, shows that the source of groundwater for the unconfined Souss aquifer seems to be composite between a direct infiltration on the High-Atlas tributaries and a remote recharge from the bordering High Atlas aquifers.