Assessment of irrigation potential of ground water using water quality index tool

Abstract

Transforming parametric concentrations into qualitative scores irrespective of unit has made the Water Quality Index a comprehensive and easy to use tool to the decision makers. As criteria of water quality vary with purpose of use of the ground water, selection of water quality parameters, involved in working out quality index for specific use, also differs. Use of Ground Water Quality Index (GWQI) technique to assess irrigation water quality is innovative in this study. Electrical conductivity (EC), sodium adsorption ratio (SAR), and residual sodium carbonate (RSC), judged as the three most important parameters to determine irrigation quality of ground water, have been used to work out GWQI in this study. Preparation of iso index maps using water quality scores, derived through GWQI tool, vividly portray the irrigation water quality status of the study area where most of the area fall under excellent and good categories. The marked difference in water quality with respect to season in some areas of southeastern and southwestern parts of the study area may be correlatable to the recharge and discharge zones of ground water respectively.