A geo-spatial approach for delineating the artificial recharge sites in Salem city using ahp and csi techniques

Artificial recharge has become necessary to safeguard groundwater resources in arid and semi arid regions. The present study deals with the delineation of artificial recharge zones as well as the identification of favorable-recharge sites in the Salem city, Tamil Nadu, India using remote sensing, GIS and multi criteria decision making techniques for augment the groundwater resources. The spatial data sets like LANDSAT8 ETM satellite imagery, Survey of India topographical map, district resources map by geological survey of India and other collateral data-collected from different agencies and departments which were used to prepare thematic layers. The thematic layers-are prepared and digitalized by using spatial analysis functionality of GIS. The weights of thematic layers on a-scale of 1 to 9 are assigned based on its relative influence on groundwater productivity. Normalized weights are-computed using pair wise comparison matrix of Satty's Analytical Hierarchy Process (AHP). All thematic layers-are integrated in GIS environment using Raster calculator to prepare a composite map representing artificial-recharge zones in the study area. The indexed artificial recharge site maps are reclassified into four classes-based on the layers Cumulative Score Index (CSI) statistical approach by utilizing the statistical information of-the resultant index map. On the basis of resulted map, the study area is classified into four favorable recharge-sites namely very high favorable (22.75 Sq.km), highly favorable (20.30 Sq.km), moderately favorable (40.55 Sq. km), least favorable (8.36 Sq.km). Intersection point of lineament with streams of second and third order are-considered as possible recharge sites. Result of the study could be very effective in the formation of sustainable-and efficient groundwater management plan of the Salem city.