S. Hema and T. Subramani
Abstract
Surface water sources are rather inadequate in peninsular India to fulfil the demand and have to be supplemented with groundwater. Productivity through groundwater is quite high as compared to surface water. Cauvery basin is one of the best regulated and fully exploited basins and no documented estimates of groundwater are available for the basin in the central part of Tamil Nadu region. The present study is an attempt to delineate the groundwater potential zones in the central part of Cauvery river basin, South India using integrated approach of Remote Sensing and GIS techniques. Various geological and geo-morphological factors play a major role in the occurrence, movement and potential of ground water sources. Survey of India (SOI) Topographic maps and LANDSAT TM satellite images were used to prepare various thematic layers such as geology, geomorphology, drainage pattern, lineaments, soil and slope, which influence the occurrence, movement, yield and quality of groundwater. All these themes and their individual features were then assigned weights according to their relative importance in groundwater occurrence. The thematic layers are then integrated using ERDAS image processing software and by employing raster calculator tools in ArcGIS platform, a composite groundwater potential index (GWPI) for the study area was generated on the basis of which the overall groundwater potential map was produced. Three categories of groundwater potential zones were delineated as poor; moderate and high. Groundwater occurrence is categorized as poor in 63.34% of the study area which substantiates artificial recharge to augment groundwater in the region.