Determination of Artificial Ground Water Recharge Adequacy in Vaniyar Sub-Basin, Tamil Nadu, India

The main aim of the artificial recharge in water resource management in arid and semi-arid regions is to increase the ground water level by surface runoff. In this Vaniyar Sub-Basin, which is in the southern part of Tamil Nadu, India, the factors such as topsoil thickness, weathered zone thickness, anisotrophy (formation compactness) and geology are considered, to determine the areas most suitable for groundwater recharge in a hard rock aquifer. Using GIS environment Thematic layers were prepared, then classified, weighted and integrated for the explained parameters. To determine the relationships between geological units and the appropriate sites for groundwater artificial recharge, geology map were derived from GSI geology map. The final integration map gives 7 suitable combinations for recharge sites based on topsoil thickness, weathered zone thickness, Dar Zarrouk parameter (Anisotropy) and geology. The excellent category is (topsoil, weathered zone thickness and anisotropy for good combination in Epidote-hornblend gneiss region), covering an area of 64.54 Km². The second favorable zone is classified as very good category is topsoil, weathered zone thickness and anisotropy for good combination in Chanockite region) covers an area of 12.64 Km². These areas are highly recommended in suitable for the construction of artificial recharge structure includes check dam, percolation tank and recharge well. The outcome of the study indicate that almost 13.05 per cent of the study area is considered as appropriate sites for artificial groundwater recharge.