Geomorphometric Analysis of Chamoli and Karnaprayag District, Uttrakhand in Respect to Hazard Zonation of The Area

Abstract

Chamoli and Karnaprayag district of Uttrakhand comprises of fragile lithological formations and lies in highly vulnerable zone in terms of natural disasters. It's latitude and longitude ranges between 29°50’N to 30°40’N and 78°40'E to 79°50'E. The area is highly prone to frequent hazards like landslide, earthquake, cloud burst and flash floods. Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) has been used for preparing Digital Elevation Model (DEM), slope, aspect and various other maps which have been used for evaluation of linear and areal parameters. The studies have been carried out on 64 selected 4th order river basins in Chamoli and Karnaprayag district using ARC GIS. There are various parameters like stream order, stream number, Bifurcation ratio, Drainage density, Form Factor, Elongation ratio etc. had been analyzed on the river basins. The lower values of Bifurcation ratio in basins represent geological heterogeneity, high permeability and less structural control. The value of Drainage Density varies between 1.3-2.2 Km-1 which implies development of coarse grained texture. The complex relationship between the values of Elongation ratio, Circularity ratio and Form factor in some basins represents that these passing through structural thrust. The anomalous values of linear and areal parameters suggest that basins of the study area are geologically, structurally and lithologically controlled. The occurrences of landslide, earthquake has reliable relation with computed parameters. Since the outcome of the study will act as precursors for natural disasters.