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Abstract

An Integrated Approach with GIS and Weighted Average for Landslide Hazard Zonation in parts of Garhwal Himalayas, India

Amit K Bhattacharya
Associate Professor
Indian Institute of Technology Kharagpur, India
amkb@gg.iitkgp.ernet.in

Rohit Kumar
Student
Indian Institute of Technology Kharagpur, India

Abstract :
Landslides are a great menace in regions around Himalayas causing wide spread damage and loss of life and property every year. It is thus necessary to build up a Landslide Hazard Zonation Map of an area, which aims at delineating the landslide vulnerable zones and at ranking them in order of the degree of hazard. The present study was carried out over part of Chamoli district, Garhwal Himalayas, India. The region is marked by highly rugged terrain with elevation values reaching 3800 m. High and vertical scarps in many areas characterize the region, while at some other places gentle slopes are present over which cultivation is done. In the present study, an integrated approach with Weighted Average on a Geographical Information System (GIS) has been used for the evaluation of natural landslide hazard zones in the study area. Five categories of controlling factors for landslides, viz., geology, slope aspect, drainage, land use/ land cover, and seismic intensity of the area has been taken into consideration. Each category was sub-divided into various sub-classes. Weightage to each of these sub-classes towards landslide susceptibility was given, and finally all these have been integrated on a GIS platform to generate the Landslide Hazard Zonation map of the area. The study area could be divided into five landslide hazard zones, namely, Very High Hazard Zone, High Hazard Zone, Moderate Hazard Zone, Low Hazard Zone and Very Low Hazard Zone.