Geographic information system-based groundwater quality assessment for drinking and irrigation purposes in transboundary aquifers of River Ravi, India

Access to safe and clean drinking water is a basic human right, and assessment of groundwater suitability for drinking purpose imparts significant role in providing clean and suitable water for human consumption. The main objective of this study was to assess the groundwater quality status of Gurdaspur district falling along international boundary of Indo-Pak, thus serving as transboundary aquifers, for drinking and irrigation purpose based on physicochemical analysis of 111 samples using standard numerical indices and GIS techniques. Shannon's entropy theory was employed to assess the groundwater quality for human consumption as it removes the subjectivity problem and integral ambiguities of groundwater systems. The results of entropy water quality index revealed that the drinking groundwater quality was found to be in excellent, good and medium water class except 5 samples which were in poor to extremely poor water class. Piper trilinear plot revealed that the main water types were Ca2+ and Mg2+-HCO3-. Mineral saturation index indicated that carbonate minerals were oversaturated and the evaporative minerals were undersaturated. The outcomes of principal component analysis indicated that the ion exchange, weathering and agricultural practices were the dominant controlling factors in the study area. Furthermore, the results of the irrigation water quality index illustrated that 3 and 65 samples were placed in 'severe restriction' and 'high restriction' class respectively indicating irrigation water as an issue for sustainable agricultural production in agrarian dominant district. The study recommends the adaptation of remedial actions particularly in the regions where drinking and irrigational groundwater quality issues are reported to ensure clean and suitable drinking water for the inhabitants.