Hydrogeochemical Characterization and Water Quality Assessment of Groundwater and Surface Water Resources in Çağlayancerit (Kahramanmaraş), Türkiye

This research examines the hydrogeochemical properties and geographical variability of groundwater in the Çağlayancerit area (Kahramanmaraş, SE Türkiye), using the analysis of four karst spring waters and one surface water reservoir. Major ions (Ca2+, Mg2+, Na+, K+, $${\text{HCO}}_{3}^{ - }$$ , Cl−, $${\text{SO}}_{4}^{{2 - }}$$ ) were examined to classify water types and hydrogeochemical processes. All water samples were categorized as Ca-HCO3 type, indicating a predominant effect of carbonate lithologies in the area. Spatial differences were noted, with Source-4 and the Zorkun Reservoir displaying increased concentrations of Mg2+, Na+, and $${\text{SO}}_{4}^{{2 - }}$$ , resulting from the breakdown of dolomitic limestone and the impacts of evaporation, respectively. Electrical conductivity fluctuated between 327 and 728 µS/cm, whereas total dissolved solids (TDS) ranged from 217 to 474 mg/L. Wilcox and USSL diagrams indicated that all samples are classified into the C2S1 and C3S1 categories, rendering them appropriate for irrigation. The Piper and Schoeller diagrams validated both chemical uniformity and localized variations. The findings align with analogous research in karst regions across Türkiye (e.g., Anzorey, Mersin, Oltu) and the Mediterranean (e.g., Tunisia, Slovenia), reinforcing the assertion that geological and climatic factors mainly influence groundwater quality. This research provides essential data for forthcoming groundwater management and conservation initiatives in karst-dominated areas.