Locating Zones of High Discharging Wells for Protection and Management of Groundwater Resources in Precambrian Metamorphic Rocks of Purulia District, West Bengal, India - A Case Study by Hydrostructural Domain Approach

Locating sites of high discharging wells in metamorphic crystalline terrain is still a difficult problem imposing inadequate protection and management for groundwater resources. The present study attempts to determine this technique in a Precambrian metamorphic rock in and around Balarampur, Purulia district, West Bengal, India using lineaments, joints/fractures and well data with the help of software approach. The joints/fracture study consists of using hydraulically significant fracture data to generate representative modal and coefficient of variance (Cv) for each domain. Lineament study incorporates estimation of the hydraulically significant FCL and their percentage of occurrence in each domain. The hydrostructural domain based study identifies areas within the shear zone (D2) and south of the shear zone (D3) as hydraulically significant region than the region to north of the shear zone (D1). The modal and Cv values of well discharges also signify D2 and D3 as hydraulically significant part of the study area. Existing wells show discrete increase in discharge from Dl. to D3 through D2, with high discharging wells (= 4000 litre per day) occurring in groups in linear fashion, defining 'well lines', in close proximity to the determined FCL. Thus the study validated the hydrostructural domain based analysis for locating high discharging wells, indicating the sites for protection and management of groundwater resources for sustainable utilization and development in Precambrian metamorphic terrain.