Assessment of Groundwater Vulnerability using GIS Based drastic Model A case study in Udupi District Karnataka State India

Abstract

i newlineABSTRACT newlineWater is an essential resource for various beneficial uses. Increased urbanization and newlineindustrialization are discharging the waste water into environment without treatment. By newlinethe runoff and infiltration the water is reaching surface and subsurface water bodies and newlinecontaminating the fresh water. Treating ground water is costly and requires proper newlineassessment. The key measure for effective management of ground water is by preventing newlinethe seepage of wastewater into aquifer. newlineThe selected study area is the Udupi district of Karnataka state where the water from newlineunconfined aquifer is used more than the surface water. The unconfined aquifers are more newlinevulnerable by the infiltration and runoff of contaminant. Prevention of ground water newlinepollution can be done by identifying the vulnerable areas which has a higher tendency of newlinepollution potential considering the hydrogeological characteristics of the area and make newlinedecision for land use in the vulnerable areas. newlineThe DRASTIC tool was proposed by US environmental protection agency (EPA) to newlinedetermine the vulnerable areas to the ground water contamination. The Primary objective newlineof the study focuses on the determination of vulnerable zones in the study area by newlineDRASTIC tool and validates the DRASTIC Vulnerability index with Water Quality newlineIndex to check the applicability of DRASTIC index in the selected study area by newlinespearman Rho co-relation coefficient. It includes the study of variation of vulnerability of newlinethe area over years. Modified DRASTIC Vulnerability index was determined by changing newlinethe weightage to obtain the improved Vulnerability Index correlation with Water Quality newlineIndex. newlineThe ground water quality analysis in the study area was done for 112 ground water newlinesamples in pre monsoon and post-monsoon season (2017). Water analysis was done for newline16 physico-chemical parameters such as pH, turbidity, chlorides, nitrates, fluorides, newlinesulphates, hardness, calcium, magnesium, iron, coliform bacteria s, potassium, sodium, newlinemanganese and phosphates