ASSESSMENT OF GROUNDWATER POLLUTION POTENTIAL THROUGH REMOTE SENSING AND GIS TECHNIQUE A CASE STUDY FOR ANEKAL TALUK, BANGALORE URBAN DISTRICT, INDIA

摘要

Groundwater is regarded to be the most valuable resources. Groundwater quality is affected by virtually every activity of the society thereby making groundwater protection complicated. The protection of groundwater is always cheaper than restoring already polluted aquifer. DRASTIC index methodology helps in the assessment of groundwater pollution potential. DRASTIC index uses a set of seven hydrogeological parameters viz., D-depth to Groundwater table; R-recharge due to rainfall; A-aquifer media; S-soil media; T-topography; I-impact of vadose zone; C-hydraulic conductivity. These parameters are weighed with respect to their relative importance. All the DRASTIC parameter layers in spatial formats are put into GIS. The layers were assigned weights and ratings and they are combined interactively in the computer system.. The DRASTIC index map was generated on a minute grid and seven categories of groundwater pollution potential zones were identified. The Drastic Index represents the relative measure of groundwater pollution potential, which helps planners and administrators in broadly screening areas for waste disposal sites. Pollution potential map also helps in evaluating alternatives for directing the financial resources and land use activities to the appropriate areas.