Isotopic signature of groundwater and climate change within a semi-arid environment

Abstract

The negative effects of climate change on water resources from arid and semi-arid environments are of great interest to academics and policymakers. In this regard, this paper aims to assess the climate change impact on water resources within semi-arid environments, with a focus on the Essaouira Basin. To assess these effects we based on the isotopic signature of groundwater. This approach shows that (a) the recharge of groundwater is ensured by the precipitation of Atlantic origin without significant evaporation. (b) low recharge rate following the decrease in the precipitation rate (16% for the period 1978–2015) experienced by the study area in recent years, (c) The presence of old or fossil water in the study area suggests a low rate of renewal and the overexploitation of the groundwater in this basin, (d) The temporal evolution of the 18O contents generally shows an enrichment character of 1–1.5‰, which can probably be due to the evaporation phenomenon following the increase in the air temperature caused by climate change. However, it can be concluded that the isotopic signature of the groundwater within the Essaouira basin has not been spared from the effects of climate change.