Groundwater recharge site suitability analysis through multi-influencing factors (MIF) in West Bengal dry-land areas, West Bengal, India

Groundwater levels are gradually declining in basins around the world due to anthropogenic and natural factors. Climate is not the only factor contributing to change in groundwater levels, population growth and economic progress are leading to increased water demand. Areas used for agricultural irrigation are expanding, necessitating the use of artificial groundwater recharge as a method to sustain pumping and enhance storage. The present study delineates potential locations of significant groundwater resources that already exist using a geostatistical approach as a method to identify potential groundwater recharge zones. The Multi-Influencing Factors (MIF) technique was applied to determine the relationship between different landscape and climatic factors that influence groundwater recharge. Factors include topography, climate, hydrogeology, population, economic change, and geology. Integration of these factors enabled the identification of potential locations of groundwater suitable for artificial recharge efforts based on weights derived through the MIF technique. We applied these weights to derive a groundwater recharge index (GRI) map. The map was delineated into three groundwater recharge zones classified by their potential areal coverage as a metric for recharge suitability, namely low, medium and high suitability, occupying areas of 8625 km2 (30.06%), 9082 km2 (31.65%), and 10,989 km2 (38.29%), respectively. Our findings have important implications for designing sustainable groundwater development and land-use plans for the coming century.