Quantitative stream network analysis for assessing form and hydrological processes of the watersheds of Kolli hills, Tamil Nadu, India

摘要

The present study attempts to bring out information relating to the form and processes of the major watersheds of the Kolli hills of southern India. For this purpose, various parameters which are routinely considered for stream network analysis such as stream ordering, numbering, stream length, bifurcation ratio, length ratio, watershed length, area, drainage density, stream frequency, form factor, length of overland flow, relief, slope, gradient, ruggedness number, relative relief, and relief ratio were quantitatively estimated for each watershed using ArcGIS software. These estimations of the watersheds were analysed to infer form and processes such as watersheds' shape, size, elongation, slope steepness and length, degree of development of stream network, degree of branching of streams, degree of terrain dissection, infiltration potential, mean annual runoff, rainfall intensity, relative potential energy, relative denudation rate, relative discharge rates, mean and peak discharge, lag time, intensity of erosion, relative amount of sediment transported, and flash flood proneness. The understanding of these forms and processes of the watersheds could serve as useful inputs for the planners in the formulation of strategies for the sustainable development of the Kolli hills.