Groundwater prospective mapping: Remote sensing and a GIS based index model approach

Abstract

The present study is concerned with the development and test of an integrated remote sensing and GIS based methodology for identification of groundwater potential areas in a humid tropical river basin. Indian Remote Sensing Satellite (IRS 1C-LISS-III) data along with other collateral data such as existing maps and field observations was utilized to extract information on the hydro-geomorphic features of the terrain. The study involves two components: (a) demarcation of groundwater potential zones (b) validation of sites with yield data. In order to demarcate potential groundwater zones, six pertinent thematic layers were integrated and assigned appropriate rankings. Layers considered were: geology, geomorphology, drainage density, slope, rainfall with infiltration factor and land cover map. The layer parameters were also rated according to their importance relative to other classes in the same theme. All the layers were superimposed and analyzed in ARC GIS� environment. A linear additive model based on the DRASTIC model concept was used to find the groundwater potential index (GPI). The map comprised of six categories of groundwater yield. To carry out more focused investigations on the potential zones, lineament maps were superimposed over it. The validity of different potential zones identified using the GIS-based model was compared with available borewell yield data and found to be in good agreement. The map generated can be used in future as a preliminary screening tool in selecting well sites and as a basic tool in land use planning for groundwater protection. � 2008 SPIE.