ETUDE HYDROGEOCHIMIQUE DES EAUX DES AQUIFERES DE FRACTURES DU SOCLE PALEOZOIQUE ET PANAFRICAINDE LA COMMUNE RURALE DE ZERMOU SUD EST DE LA REGION DE ZINDER (NIGER)

The rural commune of Zermou, the study area, is located in the southeastern part of the Zinder region. In this area, groundwater is the primary source of drinking water. The main objective of this study is to gain a better understanding of the origin of groundwater mineralization in the area using hydrochemical methods and Principal Component Analysis. The study reveals that the groundwater in the area is slightly acidic, with a pH ranging from 6.5 to 7.5, with an average of 6.8. Apart from the waters of Garin Alkali and Zarmou, where conductivity values are high, the waters are generally weakly mineralized, ranging from 73.5 to 1810u/cm, with an average of 645.88u/cm. The hydrochemical study identified four (4) types of water facies in the area. These are calcium and magnesium bicarbonate facies, the most prevalent and representing 50% of the studied waters; sodium and potassium bicarbonate facies (35%); calcium and magnesium chloride facies (10%); and sodium and potassium chloride facies (5%). Statistical analysis revealed that the various ions originate from rock weathering and mineral hydrolysis, soil leaching, and anthropogenic surface mineralization. Redox reactions also play a role. Furthermore, the studied waters are generally undersaturated with calcite and dolomite.