Delineation of Ground Water Potential Zones using Remote Sensing, GIS and Geophysical Technique in Harahua Block, District Varansi, Uttar Pradesh

Abstract

The present level of groundwater tables is falling at a rapid rate due to the withdrawal of groundwater being high in comparison to the recharge of groundwater. The research work on delineation of ground water potential zone in Harahua block, District Varanasi, Uttar Pradesh is based upon the scientific investigation of the Hydro-Geomorphology, Lithology, Drainage, Soil, Slope, Land use land cover and Geo-resistivity data. This work covers the spatial analysis for the identification of suitable structure and location for Harahua block, Varanasi district using satellite data with the help of Geographical Information System (GIS), Remote Sensing and Geophysical technique. In this study Landsat-8, Sentinel data and softwares were used for analysing the data using classification method. Digital Elevation Model (DEM) and slope maps were prepared using Shutter Radar Topographic Mission (SRTM) data. Thematic layers were prepared using GIS for base map, drainage, canal, water body, lithology, drainage, contour, soil, hydro- geomorphology and land use land cover. Analysis of ground water level through geophysical technique, thematic map like vertical electric sound location, cross section, top soil, clay thickness, saturated zone thickness, aquifer thickness, and depth to ground water was carried out. Criteria for GIS analysis have been defined for the groundwater potential capacity according to the weightage through weightage overlay method.  The result were categorized based upon the four categories i.e. Excellent, Good, Moderate and Poor. Only the excellent and good categories are suitable for establishing rainwater harvesting structure. Results indicated that, for the block of Harahua 1.81% of the area was classified to excellent, 40.22% of the area was classified to excellent to very good, 46.66% of the area was classified to very good to good, 9.22% of the area was classified to Moderate ground water potential and 2.09% of the area was classified as poor.