Integrated remote sensing and GIS-based approach for assessing groundwater potential in West Medinipur district, West Bengal, India

A systematic planning of groundwater exploitation using modern techniques is essential for the proper utilization and management of this precious but shrinking natural resource. With the advent of powerful and high-speed personal computers, efficient techniques for water management have evolved, of which RS (remote sensing), GIS (geographic information system) and GPS (Global Positioning System) are of great significance. In the present study, an attempt has been made to delineate and classify possible groundwater potential zones in the West Medinipur district of West Bengal, India using integrated remote sensing and GIS techniques. The thematic layers considered in this study are lithology, landform, drainage density, recharge, soil, land slope and surface water body, which were prepared using the IRS-1D imagery and conventional data. All these themes and their individual features were then assigned weights according to their relative importance in groundwater occurrence and the corresponding normalized weights were obtained based on the Saaty's analytical hierarchy process. The thematic layers were finally integrated using ArcInfo GIS software to yield a groundwater potential zone map of the study area. Thus, three different groundwater potential zones were identified, namely 'good', 'moderate' and 'poor'. The area having good groundwater potential is about 1400km2, which is about 15% of the total study area. The eastern portion and some small patches in the central and northern portions of the study area fall under moderate groundwater potential zone, which encompasses an area of 5400km2 (55%). However, the groundwater potential in the western, south-western and parts of north-eastern portions of the study area is poor, encompassing an area of about 3000km2. Moreover, the average annually exploitable groundwater reserve in the good zone was estimated to be 0.29MCM/km2, whereas it is 0.25MCM/km2 for the moderate zone and 0.13MCM/km2 for the poor zone. Finally, it is concluded that the RS and GIS techniques are very efficient and useful for the identification of groundwater potential zones.