Analysis of tectonic deformation on channel morphology through quantitative geomorphic indices and DEM derived drainage system

Abstract

Drainage basin dynamics of any river is controlled by geomorphic attributes which include both surface and subsurface characteristics of a watershed. These characteristics comprise erosional and deformational processes affecting the hydrological and morphological conditions of the watershed. Similarly, the tectonic setup of the watershed influences the terrain topography and geomorphology as well. The paper deals with the evaluation of DEM-derived parameters related to morphometry and tectonic setup in the Asan watershed, Doon Valley, Uttarakhand. The assessment of active tectonics in the study area is based on the parameters related to the morphometry and morphotectonic characters of the watershed. These terrain attributes are determined using Cartosat-1 DEM (10 m) using GIS to investigate the structural setting. The parametric evaluation concerning morphometric analysis helps to understand their significance in watershed prioritization and management while the tectonic analysis helps to determine the structural setup and identifying the hazard-prone area, if persists, in the watershed. The study area falls downhill of tectonically active Lesser Himalaya and Siwaliks, make it an ideal location to determine the degree of relative tectonic activity in the area. The average of measured attributes is used to evaluate the combined classification of the Relative Active Tectonic Index (Ri). The outcome reveals that the watershed is tectonically active that experienced a differential rate of tectonism and have a consistence relationship between structural disturbances and basin geometry.