GIS and Remote Sensing for Micro Level Augmentation of Groundwater Resources using WPR and CSI Techniques

Abstract

The safe development of groundwater resource mainly depends upon the groundwater recharge. Artificial groundwater recharge is essential in terrains with low natural groundwater recharge. Here a groundwater augmentation plan is prepared for hard rock terrain of Panamarathupatti block, situated in southern part of Salem district, Tamil Nadu. Using remote sensing and geographic information system (GIS) it is possible to take number of different thematic maps of the same area and overlay them on top of one another to form a new integrated layer. This study was aimed to identify the groundwater recharge potential zones, to be used for better and improved groundwater resources. The thematic layers considered in this study are lithology, slope, geomorphology, drainage density, transmissivity, Storativity and available space for recharge, which are prepared using satellite imagery and other conventional data. Each theme was assigned weights using a numerical weighted parameter rating (WPR) depending on its influence on ground water recharge. Each class or unit in the map was assigned a knowledge based ranking depending on its significance in storage and transmittance of groundwater, and these values were multiplied with layer weights using composite suitability index (CSI). The next step deals with classification of all these parameters into ‘suitable’ classes and assignment of ‘suitable’ ranks to these classes, and finally integration of all the ranked and weighed parameters in a GIS environment. Subsequently, the area is classified into different sites suitable for the artificial recharge zones. The final map shows different categories of suitability sites for construction of various groundwater recharge structures.