GIS model-based morphometric evaluation of Tamiraparani subbasin, Tirunelveli district, Tamil Nadu, India

Abstract

A morphometric evaluation of Tamiraparani subbasin was carried out to determine the drainage characteristics using GIS model technique. Extraction of the subbasin and stream network model has been developed to quantify the drainage parameters in the study area. The input parameters required to run this model are: a pour point, a minimum upstream area in hectares, and a digital elevation model. After execution, the model provides a drainage basin with Strahler’s classified stream network supported by thematic layers like aspect, slope, relief, and drainage density. The developed model reveals that the drainage area of this subbasin is 2,055 km2 and shows subdendritic to dendritic drainage pattern. The basin includes seventh order stream and mostly dominated by lower stream order. The slope of the study area varies from 0° in the east to 61° towards west. The presence of Western Ghats is the chief controlling factor for slope variation. Moreover, the slope variation is controlled by the local lithology and erosion cycles. The bifurcation ratio indicates that the geological structures have little influence on the drainage networks and the drainage density reveals that the nature of subsurface strata is permeable.