Evaluation of Morphometric Parameters Derived from CartoDEM and Aster GDEM with SOI Toposheets of Kumudvathi Watershed Basin, Karnataka, India

Abstract

From three different sources viz. survey of India topographic map (1:50,000), CartoDEM (10 mts) and Aster GDEM (30 mts) morphometric parameters are derived and evaluated. Manually digitized the drainage network from toposheets and extracted drainage network system from CartoDEM and Aster GDEM using ArcGIS 10.2 software. Basic, derived and shape parameters are considered for basin analysis. The mean bifurcation ratio of the given basin for CartoDEM & Aster GDEM are having nearby values and also indicates some sort of geological control, high stream frequency (Fs) is indicative of high relief and low infiltration capacity of the bedrock pointing towards the increase in stream population with respect to increase in drainage density, low drainage density (Dd) leads to coarse drainage texture, value of Lg for topographic, CartoDEM and Aster GDEM data indicating very fine texture & fine texture respectively. From the shape parameters the Kumudvathi watershed indicates it is sub-circular and elongated. The results from the high resolution data will have the nearby values and less of % variation, whereas in low resolution data % of variation is more and will not meet criteria.