Landslide vulnerability assessment in Gangotri valley glacier Himalaya through GIS and remote sensing techniques

Almost every year, landslide damages several villages, road connectivity and important infrastructure set-ups along with many casualties and injuries to the people living in the Gangotri valley glacier area. This glacier valley is surrounded by high peaks, and it represents one of the largest glaciers in the western Himalaya. The fluctuations in climatic conditions and prevailing glacial, fluvio-glacial and fluvial processes resulted in the diversified landforms throughout the region. In the present study, remote sensing and GIS techniques have been used to generate various models like digital elevation model, digital terrain model and maps like aspect map, slope map and altitudinal zones map of Gangotri valley glacier area. Using these models and maps, landslide vulnerability assessment was carried out which is essential for making the disaster risk management strategy for the study area. The digital elevation model shows a gradual escalation in elevation towards SW direction. Digital terrain model indicates that the number of tributary glaciers and associated landforms on either side of the valley was more in number in the past. Data of aspect map show that NE part is most sensitive for avalanche and the slope map indicates the important sites for choking of the Bhagirathi River due to debris and mass flow. The outcome of this study will be helpful in landslide vulnerability assessment along the formation of Bhagirathi River disaster risk reduction plan.