Hydrogeochemical characterization of groundwater in a coastal area, central western Senegal

One of the most serious problems affecting coastal aquifers is seawater intrusion. Senegal currently facing an increased demand for freshwater resources due to population growth and economic development in areas. In areas affected by saltwater contamination, chloride concentrations as high 8880 mg/L were measured groundwater samples taken from wells near zone, indicating deterioration water quality. Our study aims identify zones degradation quality determining chemical composition geochemical processes controlling patterns. Hydrogeochemical (Piper Chadha diagrams, chloroalkaline indices, normalized bivariate plots) multivariate statistical (Hierarchical cluster analyses) techniques used. Forty-two collected analyzed major some minor ions, electrical conductivity (EC), total dissolved solids (TDS), temperature, pH. From we able establish a diagnosis very heterogeneous this area. The average pH 7.6 about 80% have TDS below 1000 mg/L. On other hand, EC values are with conductivities Approximately, less than heterogeneous. dominant types area Na-Cl type (less 10% samples) characteristic spatial evolution salinization west east, mixed Ca-Mg-Cl fresh water/salt contact Ca-Mg-HCO 3 water-type (nearly 56% east. A hydrogeochemical zonation aquifer, based on presence different families allows us visualize highly degraded (west), (center) healthy (east) zones. Chloroalkaline indices plots show that chemistry controlled mainly water-rock interaction evaporation processes. As processes, dissolution carbonate evaporite, weathering silicate, ions exchange regulates ion chemistry.