Catastrophic Landslides in Indian Sector of Himalaya

The Himalayan geo-environment has been experiencing slope instability hazards of catastrophic dimensions in historical past. Large rocks and debris avalanche have been recognized largely in higher domains in easternmost extremity covering Sikkim and Arunachal and Northwest Himalaya encompassing Kumaun, Garhwal, Himachal, Jammu and Kashmir and Ladakh Himalayas. These domains have witnessed societal and morphological impacts due to such extreme events. The catastrophic landslides are mainly triggered by earthquakes and climate change related intense rainfall, cloudbursts, Glacial Lake outburst Floods (GLOF) etc. in different sectors of Himalaya. These cataclysmic events are caused by various proportions of geological, geomorphologic and geotechnical characteristics of slopes, relief and tectonic conditions including anthropogenic activities. Each of the recorded landslides differs greatly in their causes, triggering agents, run-out distances and impacts. A case study of recent catastrophic landslide in Garhwal Himalaya has been presented. The paper highlights importance of the historical records of catastrophic landslides and attendant changes in terrain morphology to plan for strategy for sustainable regional development.