Identification of Groundwater Potential zone using GIS techniques in Olakkur block, Villupuram District,Tamilnadu.

Groundwater is one of the greatest hidden natural resources of earth's crust and has been ubiquitous occurrence. Being an agrarian state, Tamilnadu basically depends upon its water resources for agriculture activities, food production and domestic uses. Groundwater has emerged as an important and indispensable resource in the absence surface water resources to meet out the different sectoral demands. With the increasing use of ground water for various activities, the fast decline in ground water takes place. In order to prevent the aquifer from fast depletion, the artificial recharge is resorted to. Keeping in mind to avoid fast decline in groundwater levels in Olakkur block of Villupuram district, a study has been undertaken to identify the favorable areas for groundwater recharge zones with an aerial extent of 270 sq.Kms, using remote sensing data and GIS techniques. The various thematic maps such as Soil, Geology and Geomorphology extracted from satellite imagery IRS IC - LISS III PAN Merged with spatial resolution of 23.5m, Slope (%) extracted from SOI toposheets with the scale of 1:50,000 and rainfall map extracted from the water table data and rainfall data. Using spatial analysis tool in Arc GIS 9.2, the above themes have been integrated and the areas suitable for groundwater zones have been obtained. The areas for groundwater recharge have been categorized in terms of highly favourable, moderately favourable and poor recharge zones.