Fuzzy logic algorithm based analytic hierarchy process for delineation of groundwater potential zones in complex topography

Groundwater crisis under the changed climate scenario has now become a global concern. Land use and land cover change and rapid urbanization are some of the prime causes of it. Aquifers are in a vulnerable condition due to the extensive abstraction and over exploitation as the groundwater draft exceeds the groundwater recharge. It is in this context, the present study has been carried out to identify groundwater potential zones of Garbeta block of Paschim Medinapore district of West Bengal, India, which is located in a critical terrain condition and faces extreme water scarcity in terms of both surface and groundwater availability. The region experiences an average annual groundwater level fluctuation between 9 and 11 m. Demarcation of the groundwater potential zones has been made using Fuzzy Analytical Hierarchy Process (Fuzzy AHP) integrated with geospatial techniques. Fuzzy weights have been entrusted to eleven physical parameters namely land use and land cover, soil, geology geomorphology, lineament density, drainage density, relative relief, distance from river, slope, groundwater level fluctuation and normalised difference water index (NDWI), and the final map has been prepared within geospatial environment. The groundwater potential zones have been classified into five classes: very low potential (18.30%), low potential (26.42%), moderate potential (25.99%), high potential (19.55%) and very high potential (9.75%). The calculated results have been validated through field based groundwater level survey. Such studies will provide new vision and incur valuable information to the stakeholders for sustainable water resources management and effective identification of suitable locations for groundwater extraction.