Integrated Geohydrological Studies in the Sedimentary Part of Gadilam River Basin, Cuddalore District, Tamil Nadu

摘要

Water is a precious natural resource, without which there would be no life on Earth. Human beings body weight is also composed of two-third water. Our day to day life depends on the availability of inexpensive clean water and safe ways to dispose it after use. As a source of water, groundwater obtained beneath the earth's surface is often cheaper, more convenient and less vulnerable to pollution than surface water. Gadilam river basin covering sedimentary part lies between Latitudes 11°25'00 to 11°45'00 N and Latitudes of 79°18'00 to 79°47'60 E. Earlier Public Works Department (Government of Tamil Nadu), 1992 has done geohydrological field data collection including geological mapping; meteorological data was collected from Public Work Division (PWD); Remote sensing study was done through Landsat TM satellite imagery. The Landsat TM and SRTM satellite images were geometrically rectified with reference to the Survey of India (SOI) topographical sheets of 1:50,000 scale using ERDAS IMAGINE 8.7 software. From SOI toposheets and later using linearly stretched False Colour Composite (FCC) of Landsat TM satellite data and by using other image processing techniques were used to interpreted to map the geomorphology of this region. Water table fluctuations map was prepared using pre and post monsoon water level data. Water level fluctuation map is prepared by using spatial analyst tool of Arc GIS software. From the fluctuation map, it was found that maximum recharge is found in the central and southern part of the study area as water table is occurring at 43 m below the ground level. North-Eastern and western part of the study area shows minimum rise in water level with less than 7 m.