Groundwater Recharge and Salinity Problem in South-western Mauritania

Abstract

The south-western Mauritania characterized by semi-arid environment, located between the Senegal River in the south, and the Atlantic Ocean to the west. The objective of this work is to combine the groundwater recharge and salinity problems for identifying the groundwater recharge in response to current and past environmental changes. The field survey carried out from 2010 to 2012 monitoring the water level and salinity in the study area.Results show that the water table levels appeared quite stable. However, combining groundwater recharge and salinity revealed that the dynamics of the aquifer is influenced by many changes particularly when Diama dams constructed and now regulating the river flow. The main source of the aquifer recharge is lateral infiltration from the Senegal River, and precipitation to a lesser extent. The important effect of evaporation on surface waters before and during their infiltration is strongly marked salinity signature. We found some seasonal fluctuations in the water (about 0.5 m) that could be related to the infiltration of rain but these points deserve to be tracked more accurately. The study has also been studied near the Senegal River, where the delta of Senegal River, local rise and smoothing a fluctuation of groundwater has been recorded.