Contribution of multivariate statistical techniques in the hydrochemical evaluation of groundwater from the Ouargla phreatic aquifer in Algeria

A hydrochemical evaluation of the hydrogeological surface aquifer of Ouargla was conducted using 17 samples of water. The analysis of the samples focused on the determination of calcium, magnesium, sodium, potassium, chloride, sulfate, bicarbonate, and nitrate, while electrical conductivity, temperature, and pH were measured on the ground. The obtained data are processed by multivariate techniques with a varimax rotation approach after standardization. The chemical data follow four factorial axes that provide a cumulative total variance explained by 67 %. Considering the EC as an additional variable, the matrix components after varimax rotation have identified a first axis related to NaCl, a second axis associated with CaSO₄, a third axis of HCO₃ and a fourth axis of NO₃. These variables control a significant part of the chemistry of the groundwater in the region of Ouargla.