Delineation and Evaluation of Groundwater Quality by using GIS mapping system and Statistical Approaches in Southern Punjab, Pakistan

Abstract

The groundwater is the second largest source of water in Pakistan. This study deals with the delineation and evaluation of spatial variations in the groundwater quality in Multan, Khanewal, Lodhran, Vehari, Pakpattan and Sahiwal district of Southern Punjab, Pakistan. The three major indicators such as EC, SAR and RSC (Electrical Conductivity, Residual Sodium Carbonate and Sodium Adsorption Ratio) are used and appraisal for irrigation to check groundwater quality via GIS, GS+ software and statistical analysis. The groundwater samples were evaluated for its applicability in irrigation and for mapping consequence . The parameters analyzed were compared with Standards that were adopted by WAPDA, PID and PCRWR. Kriging interpolation maps were delineated with three zone layers such as good (weight = 3), marginal (weight = 2) and bad (weight = 1). It was concluded that the area under marginal and hazardous groundwater quality with low weights was significantly increased from 2 to 10% and 7 to 40% in pre- and post-monsoon respectively due to EC, SAR and RSC parameters. Most of the study area (> 35%) contaminated was due to EC parameters. Most of the study area (tehsil Kabirwala) was observed with low quality against all discussed quality parameters in both season. The groundwater quality parameter weightage decreases from northeast to southwest of study region. Low weightage zones were observed in lower part of the area. It is recommended that in high vulnerability area artificial well recovery, auriferous storage and rain harvesting techniques should be adopted specially in lower part to reduce salinity of water. The policy maker should make policies about regulation of water resources with good quality for best utilization of water for agricultural and industrial use.