Modern and Past recharge of the Saharan Aquifer Systems by coupling geochemical tracers (14C, 36Cl,…) and hydrological modeling

Modern and Past recharge of the Saharan Aquifer Systems by coupling geochemical tracers (14C, 36Cl,…) and hydrological modeling

Project description: 
Worldwide demographic pressure, urbanization, economic growth and development of irrigated agriculture all contribute to massive increases in water demand that seriously jeopardize the availability, quantity and quality of the water resource. The Maghreb and the circum-Sahara area are particularly vulnerable to these threats because climate change amplifies this water stress by impacting the water balance as a whole, and groundwater recharge in particular. In these regions, groundwater is of strategic importance since surface water bodies are scarce. 
However these massive deep groundwater reservoirs that were artesian basins in majority are subject to intense mining since the 1950’s. This has led to a substantial decline in the piezometric surface, as witnessed by the drying up of naturally flowing springs, drawdowns in pumped wells or loss of artesianism. This raises the question of the renewability and sustainability of this resource. 
in order to face this challenge, this project aims at better describing the modern and past recharge of two aquifer systems : the North-Western Saharan Aquifer System (NWSAS) and the Nubian Sandstone Aquifer System (NSAS).