CLIMATE CHANGE IMPACT ON HAUTERIVIAN AQUIFER OF ESSAOUIRA BASIN (MOROCCO)

Abstract

Climate variability is a phenomenon whose causes are difficult to determine, can be manifested by recurrent episodes of drought, desertification, scarcity of water and change their chemistry, soil erosion and salinization. This variability may have effects on natural resources such as groundwater. To decipher the impact of climate variability on groundwater from the Hauterivian aquifer of Essaouira basin, ruled by a semi-arid climate, three approaches were used: (i) the piezometric technique that allowed drawing piezometric maps of the aquifer from 1976 to 2015. It showed that the water level from this aquifer is closely related to precipitation. (ii) The hydrogeochemical approach revealed an evolution of chemical facies from Na-Cl to Mg-HCO₃ type between 1996 and 2015. (iii) The isotopic tool was used to determine (1) a local meteoric line (LMWL) close to the global meteoric line (GMWL) characterizing precipitation of oceanic origin and (2) the charging altitude of the aquifer based on ¹⁸O.