Assessment of the Intrinsic Vulnerability to Groundwater Contamination in Lahore, Pakistan

This study was intended to map intrinsic vulnerability of groundwater contamination in Lahore using GIS based DRASTIC model. The final output of DRASTIC model was reclassified into three equal interval classes, corresponding to low, moderate and high vulnerability regions. Most of the study area was found to have low to moderate vulnerability, with 27.48% area of low, 66.48% of moderate and only 6.04% area of high vulnerability. Most of the drinking water wells are installed in the residential area of the city, which shows low chances of contamination due to deep water table and almost no recharge. However, an industrial drain is located in the high vulnerable area in the southeastern part of the study area. The previous studies are in agreement with vulnerability zones. Further to remove any doubt in the suitability of assigned weight, map removal sensitivity analysis had been carried out. The assessment of the sensitivity analysis had been made through visual as well as quantitative methods. Priority order for contribution of the parameters in the vulnerability for the study area is D>I>C>R>A>T>S.