Application of geospatial techniques in delineation of groundwater potential zones of Vannathangarai Watershed of Noyyal River Basin, Tamil Nadu, India

Abstract

In ancient times, the venerable Greek philosopher, Thales Miletus is believed to have proclaimed that “the best of everything is water”. Down the centuries, Leonardo da Vinci extolled water as the “driver of nature”. It is difficult to conceive of any facet of human development that does not ensure a ready availability of water (Ghosh Roy, 2015). Water is the most abundant substance on Earth, the principal constituent of all living things, and a major force constantly shaping its surface (Chow, Maidment & Mays2010). Groundwater is widely distributed under the ground and is a replenishable resource, unlike other resources (Raghunath 2018). The Vannathangarai watershed has been chosen for a pilot study for the present research using geospatial techniques.The fundamental goal of the study is to identify potential groundwater zones for the appraisal of groundwater availability in Vannathangarai watershed using geospatial tools. There is considerable change in the land use and cropping pattern in the study area over the last few years. Over dependence on groundwater for domestic, irrigation and industrial purposes in the area has led to the lowering of the water table and caused water scarcity. All these activities have made the water contaminated beyond permissible limits. In this scenario, it is high time to have a study on groundwater potential zones in the area. The identification of groundwater prospecting zones can be identified with the help of overlying different thematic layers like Geomorphology, Geology, Soil, LULC, Drainage density, with help of Remote Sensing and GIS techniques. The normalized weight of the individual themes and their different features were obtained through the Saaty’s Analytical Hierarchy Process (Saaty, 1980). Each layers of the theme were given different ranks, depending on their significance in groundwater prospects. Based on all these parameters and weightages, the potential zones are identified. The identification of Potential zones in the area will help the planners for having a proper management in the area where ground water is at high risk.