Morphometric analysis for peak discharge estimation of sub and micro watersheds of Vedavathy river sub basin, Karnataka

Abstract

IRS and GIS technology are extensively used for basin analysis which helps in monitoring the development and management of watershed and its catchment areas. The present study was carried to estimate peak discharge of two mini and micro watershed of the Krishna river basin, the two watersheds selected for the above study are Chikkur sub-watershed and Lailapura micro watershed which forms a part of Vedavathy river sub-basin and falls under Krishna river basin lying in between Karagunda and Hiriyur village of Chikamagalur & Hassan districts in Karnataka. The satellite image used for the study are Ortho_rectified Cartosat -1(2.5m), digital elevation model (DEM) data & LISS-IV (5.86m) are used for extraction of basin Morphometric parameters, database generation using NRIS resource layers and Automatic delineation of the watershed under Arc GIS Environment. Morphometric Analysis of Chikkur subwatershed have shown less relief ratio, high ruggedness number, time of concentration, drainage density stream frequency, mean bifurcation ratio, and less form factor. Lailapura micro watershed has shown high relief ratio, form factor and time of concentration fewer ruggedness numbers, stream frequency. The peak discharge of Chikkur subwatershed is 46.56 cusecs and Lailapura micro watershed is 10.31 cusecs for 160mm of rain respectively. Keywords: ­ sub­watershed, Krishna river basin, Vedavathy river sub­basin, and Morphometric Analysis, peak discharge estimation