Delineation of Groundwater Potential Zones in Arid Region of India-A Remote Sensing and GIS Approach

The present research is an attempt to find out the groundwater potential zones within an arid region of India supported by the scientific investigation of lithology, geomorphology, geohydrological characterization of geological formations and their interrelationship. Thematic layers of drainage, lithology, geomorphology, lineaments, slope, soil, digital elevation model, rainfall, landuse/land cover and well inventory have been generated by using ancillary data, digital satellite image, water level data of 90 observation wells for last 11 years (2000-2010), litholog data along with ground truthing. The groundwater potential zones have been classified into five categories like very poor, poor, moderate, good and excellent. The potential zones were obtained by weighted overlay combination using the spatial analyst tool in ArcGIS 9.2. During weighted overlay analysis, the ranking was given for each individual parameter of each thematic map and weights were assigned according to their influence such as lithology (20 %), geomorphology (15 %), lineament density (15 %), drainage density (15 %), soil (10 %), slope (10 %), rainfall (5 %), land use and land cover (5 %) and digital elevation model (DEM) (5 %) and it was found that the potential zones in terms of very poor, poor, moderate, good and excellent zones covered 13.7 %, 42.8 %, 27.3 %, 10.8% and 5.4% respectively of the total area. The result also has been validated by yield data collected from existing sources and it confirms that the higher yield categories are falling within excellent groundwater potential zones where yield ranges from 23 to 40.3 l/s and lower values ranging from 8.1 to 10.6 l/s are falling within poor groundwater potential zones.