Assessment of Groundwater Vulnerability Zone in Mandideep Industrial Area using DRASTIC Model

Modelling of groundwater movement may prove to be a tool for policymaking, management of land-use and surface water resources, and for future prediction of groundwater contamination level. The DRASTIC model was applied to determine the vulnerability index for the groundwater potential zone by using spatial thematic layers for Mandideep located in the district of Bhopal and Raisen, Madhya Pradesh, India. The model combines the environmental and geological properties of the area under consideration. Further, the sensitivity analysis was performed to assess the impact of each thematic layer. The model was later validated by comparing its final result against the observed nitrate concentration (NO3-N). The DRASTIC Index was found within the range of 80-193 which was further divided into three vulnerable zones. An area of 65 km(2) comes under the low vulnerable zone (80-122), 110 km(2) of the area comes under the moderate vulnerability zone. The high vulnerable zone was spread over an area of about 92 km(2). The nitrate concentration (NO3-N) was observed as below 2 mg/L in the areas of low vulnerable zone and increased to 2-10 mg/L in the moderate zone, whereas in high vulnerability zones, it was found to be above 10 mg/L which was beyond the permissible limit of 10mg/L as per WHO. Therefore, high vulnerability zones need immediate attention to manage the nitrate concentration in drinking water. Geospatial techniques and analysis of data are quite useful for reaching such a decision.