Hydrochemical Characterization and Water Quality of the Continental Intercalare Aquifer in the Ghardaïa Region (Algerian Sahara)

This study investigates the hydrogeochemical characteristics and water quality of the Ghardaa Continental Intercalare (CI) aquifer for domestic purposes and agricultural irrigation. Twenty-eight (28) grondwater samples were collected and analyzed for different physicochemical parameters. The result of the hydrochemical analysis illustrates that three facies dominate the CI waters: SO 4 -Na, Cl-Na, and HCO 3 -Na. The analysis of the correlation matrix and the characteristic ratios, as well as the calculations of the saturation indices of the main minerals, show that the mineralization of the waters is linked to the dissolution of evaporites (gypsum and halite in particular) and the cationic exchange phenomenon. The assessment of the potability of the water by using the water quality index (WQI) method shows three classes of water quality, namely, excellent (14.28%), good (7.14%), and poor (78.58%). The agricultural water quality was assessed using the parameters; EC, SAR, Na%, KR, PI and MH. The results show that the waters of the continental intercalare aquifer are generally of good quality for irrigation. However, the high salinity of the waters requires good drainage of the cultivated soils.