Application of GIS in ground water quality mapping for Varanasi city

Abstract

Ground water remains the drinking water source for a significant portion of population in India. In present study, a detailed program of ground water sampling and analyses have been done from 25 tube wells and 18 open wells of Varansi, UP (India). Chemical characteristics included nitrate, fluoride pH, dissolved oxygen (DO), BOD5, electrical conductivity (EC), total dissolved solid (TDS), sulfate; chloride and alkalinity. The open wells and tube wells were evaluated for their suitability as a source for drinking purpose. The results indicate that the tube well waters in the area are generally safe for drinking, although alkalinity in many samples is beyond desirable limits for the purpose. TDS is also found high at many places. Water samples from open wells at two places are found to have nitrate concentrations beyond permissible limits. Around 88% of samples are found to have fluoride concentrations less than 1.0 mg/ L. Geographical Information System (GIS) based water quality maps and contours of water quality parameters for Varanasi city have been prepared. © Scientific Publishers 2014. All rights reserved.