Introduction :- 

According to Global Fatal Landslide Database (GFLD), Asia was found to be the most-affected continent where 75% (India = 20%) of landslides occurred, with a substantial number reported along the Himalayan Arc. As per global database on landslides, the world's top two landslide hotspots exist in India: the southern edge of the Himalayan arc, and the coast along south-west India where the Western Ghats are situated. According to Geological Survey of India (GSI), about 12.6 % of the total land mass of India falls under the landslide-prone hazardous zone.

Vulnerability of Sikkim's: 4,895 square kilometer area is sensitive to landslides, of which 3,638 sq km area is surrounded by human population, roads and other infrastructure.

About Warning System :-

• It will help in saving lives and loss to property by issuing advance alerts by 24 hours.
• The warning system consists of over 200 sensors that can measure geophysical and hydrological parameters like rainfall, pore pressure and seismic activities.
• It has been deployed by the researchers of Kerala based Amrita University in collaboration with the Sikkim State Disaster Management Authority and partly funded by the Ministry of Earth Sciences.
• University had earlier installed a landslide warning system in Kerala's Munnar district.

About Landslide :-

• Definition: Landslides are downward and outward movement of slope materials such as rock debris and earth, under the influence of gravity.
• Major reason: Landslides are triggered by natural causes like vibrations from earthquakes and the build-up of water pressure between soil layers due to prolonged rainfall or seepage. In recent decades, manmade causes have become significant in triggering landslides, including removal of vegetation from the slopes, interference with natural drainage, leaking water or sewer pipes, modification of slopes by construction of roads, railways, buildings etc.
• Human-Triggered Fatal Landslides are increasing at the highest rate in India, where 28% construction-triggered landslide events occurred during 2004-2016, followed by China (9%), Pakistan (6%), the Philippines (5%), Nepal (5%) and Malaysia (5%).
• Weather Induced Landslide: Landslide occurrence peaks during the northern hemisphere summer, when cyclones, hurricanes and typhoons are more frequent and the monsoon season brings heavy rain to parts of Asia.
• Illegal Mining: Landslides triggered by hill-cutting are a problem in rural areas, where many people illegally collect material from hill-slopes to build homes. Fatal landslides were found to be more common in settlements, along roads and at sites rich in precious resources.
• Earthquake-Triggered Landslides: The landslide-prone Himalayan terrain also belongs to the maximum earthquake-prone zones where earthquakes of Modified Mercalli intensity VIII to IX can occur, and thus, are also prone to earthquake-triggered landslides.
• Flash Flood Phenomenon: Landslide Lead to formation of artificial lake, which can trigger flash flood in the region affected.
• Economic Cost: Landslides are the third most deadly natural disasters on earth with $400 billion being spent annually on landslide disaster management. About 70 hydropower projects in Himalayas at risk of quake-triggered landslides.

National Disaster Management Guidelines on Management of Landslides and Snow Avalanches :-

• Developing and continuously updating the inventory of landslide incidences affecting the country.
• Landslide hazard zonation mapping in macro and meso scales after identification and prioritisation of the areas in consultation with the Border Roads Organisation, state governments and local communities.
• Taking up pilot projects in different regions of the country with a view to carry out detailed studies and monitoring of selected landslides to assess their stability status and estimate risk.
• Setting pace setter examples for stabilisation of slides and also setting up early warning systems depending on the risk evaluation and cost-benefit ratio.
• Complete site specific studies of major landslides and plan treatment measures, and encourage state governments to continue these measures.
• Setting up of institutional mechanisms for generating awareness and preparedness about landslide hazard among various stakeholders.
• Enhancing landslide education, training of professionals and capacity development of organisations working in the field of landslide management.
• Capacity development and training to make the response regime more effective.
• Development of new codes and guidelines on landslide studies and revision of existing ones.

• Establishment of an autonomous national Centre for landslide research, studies and management.