Landslide Hazard and Risk Assessment Along NH-108 in Parts of Lesser Himalaya, Uttarkashi, Using Weighted Overlay Method

The present study is focused on the landslide incidences which are very frequent in the Himalayan region. Economy in most of the Himalayan region thrives more on tourism; hence, it is essential to take proper attention in these areas. The objectives of the present study include generation of a landslide inventory, damage assessment, hazard mapping and subsequently risk analysis. The aim is to identify the causative factors responsible for landslide occurrences in these areas and then prepare susceptibility and vulnerability zonation maps. The study area is a 46 km long stretch of NH-108 covering 184 km2 of the area in Uttarkashi district of Uttarakhand, India. The entire analysis is carried out using weighted overlay approach in ArcGIS software. The susceptibility map of the region is prepared and categorized from low to very high susceptible zones. Accordingly vulnerability and risk map of the region are also prepared. The entities considered in risk assessment include agricultural land, roads and places of human settlements. The validation of the analyses results is carried out through field investigations and satellite imageries.