Estimation of Hypsometric Integral and Groundwater Potential Zones of Amarja Reservoir Catchment, Karnataka, India using SRTM Data and Geospatial Tools

Abstract

Hypsometric integral always play a significant role in watershed health condition. It is nothing but the total
time taken in reduction of land area to its vile. Drainage network and studies of various landform features always help in
the search of groundwater resources. Morphometric parameter of a drainage basin always helps to understand water use
and land use of the basin. The present study aims to find out the geological stages through hypsometric integral values
and groundwater potential zones using morphometric parameters to classify it into very good, good, moderate and poor
zones using GIS tools. The total area of catchment is 544.76 km2, which is surrounded by Deccan traps. The catchment
is further separated into 5 sub-basins on the basis of 4th order stream to get the more specific result. The SRTM (Shuttle
Radar Topography Mission) data have been generated from USGS website and further analysed to identify the drainage
pattern, slope, contours etc. using ArcGIS 10.0 software. The most important parameters like linear, areal and relief for
groundwater investigation have been analysed. The analysis revealed that the hypsometric integral value of sub-basin IV
of Amarja reservoir catchment is 0.30 which is showing the late mature stage of the basin. Apart from that, the values of
sub-basins II, III and V are 0.54, 0.50 and 0.43 respectively, represent the mature stage while sub-basin I has an integral
value of 0.67 which represents the young stage of the basin and it is more susceptible for erosion. Drainage pattern of the
catchment could be mainly described as sub dendritic to dendritic. Drainage texture was found to vary from 0.41 to 1.16
which is an indicative of massive coarse to granular texture. An average bifurcation ratio of basin is estimated 3.51 which
is an indicator of structural control over the basin. Slope values were found to be in a range from 0.71 to 5.73 degree
which indicates very gentle to moderate slope.