Assessing Surface Water Vulnerability Zones in Mahanadi River Basin, Odisha, India: An Integrated Approach Using GIS and MCDM

Evaluation of surface water and their controlling processes are very important for the sustainable utilization of surface water in any region. Analytical techniques coupled with GIS, entropy-based water quality index (EWQI) and Multicriteria decision making methods (MCDMs) have been used to identify suitable surface water sites in Mahanadi River, Odisha for drinking purposes. A total of 20 samples from 19 stations were collected and analyzed for 8-year (2015–2023). The study revealed that in the investigated area, 84.20% of the final EWQI value can be classified as having excellent potential, while 10.53% are categorized as having poor potential. Moreover, 5.26% are identified as potential for unsuitable for drinking. COPRAS and GRA analysis is used to validate these findings, demonstrating that both these techniques, achieves an accuracy of 94% in identifying surface water potential zones in the region. This study utilizes the best method derived from both models to identify 19 suitable locations for best drinking water sites. The overall results suggest water quality in most parts of the investigated region is suitable for human consumption, with an exception of ST-(8), (9) and (19). According to the research, anthropogenic and geological activity have negatively impacted these sites, and a proper management strategy is required to prevent additional contamination and pollution of the local surface water.