Geospatial Modelling of Groundwater Fluctuation Using Remote Sensing and GIS-A Case Study for Hosur Union

This paper describes the study of groundwater fluctuation in the study area using remote sensing and GIS technique. In this study, Hosur Union of Krishnagiri district, Tamil Nadu, was selected as the study area. The base map of the study area was prepared by using Survey of India Toposheet at a scale of 1:50000. The groundwater fluctuations were studied for varying rainfall intensity. The analysis was carried out using spatial interpolation technique and Thiessen polygon method. For the analysis by spatial interpolation technique, the water level fluctuations for every 4 years interval were considered. In this technique, spline method was used to create the continuous surface for groundwater data. This method considers the distance between both unknown points and known points and measures the spatial correlations between two points so that the weights can change according to the spatial arrangements of samples. In Thiessen polygon method, Voronoi polygons were created so that every location within a polygon is closer to the sample point in that polygon than any other sample point. The Voronoi mapping tool provides a number of methods for assigning or calculating values to polygons. The results by both the methods indicated that the overall groundwater potential is low in the study area.