Groundwater suitability analysis for drinking using GIS based fuzzy logic

In the last few decades, overexploitation and poor management of groundwater have exposed its resources to undue risk, which makes the assessment of groundwater quality and determining its suitability extremely crucial. The current study has been undertaken with an aim to analyze groundwater suitability for drinking by utilizing fuzzy logic in the geographical Information System (GIS) platform. Water samples were analyzed for various physicochemical parameters collected from different sampling stations of the Agartala Municipality. Principal Component Analysis (PCA) and Ordinary kriging (OK) were used for variable reduction and mapping of the physicochemical parameters. The best fuzzy overlay operator for the groundwater suitability map was determined based on correlation coefficient values between water quality index map and suitability maps. The results of the correlation analysis show a high positive correlation between Cl- with EC (Electrical conductivity) and pH with HCO3-. The groundwater of the study area is mostly acidic, with elevated iron levels along with pockets of high nitrate concentration. Fuzzy GAMMA (0.9) overlay method was selected as the best overlay operation for suitability analysis. Suitability analysis results revealed that 24.6%, 28.6%, 46.7%, of the total surface area is unsuitable, moderately suitable, and suitable respectively. This study demonstrates the capability of fuzzy logic integrated with the GIS platform to determine the groundwater suitability for drinking. The proposed methodology can be exploited as a comprehensive tool for any other suitability analysis.