Characterization and evaluation of the factors affecting the geochemistry of surface water of Koudiat Medouar Basin, Algeria

Abstract

Hydrochemistry of surface water in Koudiat Medouar Basin, Algeria was used to assess the quality of surface water for determining its suitability for drinking and agricultural purposes. In the three stations, there is a good correlation between the electrical conductivity and elements Ca, Mg, K, Cl, SO₄ and HCO₃. In order to determine the geochemical nature of water, the data was interpreted using the Piper diagram wherein the results show the predominance of Ca-Mg-HCO₃ or Ca-Mg-HCO₃-Cl water type in the Oued Reboa, Ca-Mg-HCO₃ or Ca-Mg-Cl-HCO₃ water type in the Oued Timgad and Ca-Mg-Cl-HCO₃ water type in the Reservoir dam. Principal components analysis results revealed that surface water quality was mainly controlled by geology, agricultural uses and domestic discharges. All the surface water samples in Oued Timgad fall in the field of C3S1, indicating high salinity and low sodium. Most of the surface water samples in Oued Reboa and in the reservoir dam fall in the field of C2S1, indicating medium salinity and low sodium. Based on RSC values, all the samples of the three stations had values less than 1.25 and were safe for irrigation.

Key words: Surface water, principal component analysis, drinking and irrigation water quality, Koudiat Medouar Basin, Algeria.