A Comparative Analysis of Landslide Characteristics of the Himalayan and Western Ghat Mountain Belts
摘要
The landslides in the Himalayas and the Western Ghats are prime examples of devastating hazards in India and potentially across the globe. Studies conducted globally report that India, along with its neighboring countries, experiences the highest number of landslides and fatalities due to these events. The geographical position of the Himalayan belt places it in a collision zone where stresses and resulting deformation are very high. External triggering forces such as earthquakes, rainfall, storms, and avalanches make the area prone to landslide activities. In the present study, a comparison has been made between the spatial distribution, size, and characteristics of landslides in the Kangra district of Himachal Pradesh and the Idukki district of Kerala in India. Both regions are hill stations that attract many tourists every year. They are distinct in terms of geology, geomorphology, and tectonic activities, making them suitable counterparts for analyzing landslide activities. Idukki is predominantly a gneissic terrain with intense chemical weathering and high monsoonal rains, while Kangra’s geology mostly belongs to the Lower Sivaliks, consisting of sandstone, shales, conglomerates, etc., and is sandwiched between two major thrust zones. Landslide activities in both areas are a major concern, mostly arising due to rapid urbanization, unplanned excavation, and intense rainfall, a major triggering factor of landslides. The study shows that lower elevation and steeper slopes are more critical factors in Idukki, while gentle slopes are more critical in Kangra. The size of the landslide is important as large volumes of dislodged material can lead to large-scale devastation. The slope angle, elevation, and slopes far from road networks largely control the size of landslides in these areas.