Multi-faceted approach for comprehensive groundwater quality assessment of Karamana river basin in Kerala, Southern India

A multifaceted strategy was adopted in this research to analyze the groundwater quality in the Karamana River Basin in Southern India. A total of 22 groundwater samples were measured for physicochemical parameters (pH, TDS, temperature), cations and anions and trace elements. Secondary data on geology, hydrogeology and other relevant information from various sources was compiled. Results indicate that the groundwater temperatures ranged from 26 to 30 °C and pH values ranged 6.3-8.0 (average 7.26) suggesting a slightly alkaline nature. EC – expand, varied widely, with 43.5% of samples falling under brackish category. Na + and HCO 3 − were found to be the dominant cation and anion, respectively. Heavy metals (Cd, Cr, Co, Cu, Fe, Ni, Zn) were measured and found to be exceeding drinking water standards in some samples. The water quality was generally complied with WHO and BIS guidelines, however, heavy metal presence raises concerns with regard to drinking purposes. Correlation analysis revealed strong positive correlations between TDS-expand and major ions. PCA – expand, indicated three components anthropogenic, evaporation and rock-water interaction) as the main processes controlling groundwater chemistry. The Water Quality Index (WQI) indicated that potential contamination sources in the Karamana River Basin include agricultural runoff, domestic sewage, and localized industrial activities. This study provides critical insights into groundwater quality, geochemical processes, and human impacts to aid in sustainable management.