Delineation of Groundwater Potential Zones in Hard Rock Terrain in Kashipur Block, Purulia District, West Bengal, using Geospatial Techniques

Abstract

The rapidly increasing need for water has put tremendous pressure on groundwater resources in areas where it is the prime source of water. The objective of this study is to delineate groundwater potential zone in Kashipur Block, Purulia district, West Bengal with dry climate and hard rock terrain. In the present study, groundwater potential zones for the assessment of groundwater availability in Kashipur Block of Purilia District, West Bengal, has been delineated using remote sensing and GIS techniques. Survey of India toposheets and IRS-1C—LISS III satellite imagery. They are used to prepare various thematic layers, e.g., hydrogeomorphology, slope and lineament density. The maps were then transformed to raster data using feature to raster converter tool of software like MicroImages TNT mips pro 2012. The raster maps of these factors are allocated to a fixed score and weight computed from multiinfluencing factor technique. Each weighted layer is statistically computed to get the groundwater potential zones. Weighted Index Overlay modeling technique was used to develop a groundwater potential zone map with three weighted and scored parameters. Although the area is characterized by hard rock, it has groundwater prospective zones due to fracturing, weathering and the presence of valley fills overlying a planation surface. The area has been categorized into four distinct zones- excellent, good, moderate and poor. Excellent groundwater potential zones constitute 1.5% of the total block area, good groundwater potential zones occupy majority of the block, covering approximately 53%, and the moderate potential zones occupy about 45% of the total block, poor potential zones occupy very small portion 0.5%. The results reveal that the modelling assessment method proposed in this study is an effective tool for deciphering groundwater potential zones for proper planning and management of groundwater resources in diverse hydrogeological terrains