India's Tectonic Plate Boundaries

3D MAP of INDIA

One of the biggest catastrophes that plaque India's homeland are floods.

Breakdown of natural disasters in India per type of event and nature of losses  

	Natural disasters	Material loss	Human loss
Floods	52%	63%	32%
Hurricanes	30%	19%	32%
Landslides	10%	-	2%
Earthquakes	5%	10%	33%
Droughts	3%	5%	1%
Total	100%	100%	100%

Source : World Bank

 Landslides in India

• This danger affects at least 15% of the country's land area in India ( approx. 0.49 million square Km.)

• It is highly common in geo dynamically active domains such as the Himalayan and Arakan-Yoma belts in the country's northeastern sections, as well as in comparatively stable domains such as the Meghalaya Plateau, Western Ghats, and Nilgiri Hills.

• The Nilgiri Hills, located at the confluence of the Eastern and Western Ghats, display numerous landslide scars as a result of their location in a zone of high intensity and prolonged rainfall where the overburden is vulnerable to over-saturation.

• Kerala (2018), Himachal Pradesh (2018), Uttarakhand (2018), Tamenglong-Manipur (2018), and Kalikhola, Manipur (2018) are some recent big events (June 2017).

• The Intergovernmental Panel on Climate Change (IPCC) concluded in its most recent report that a worldwide rise of 1.5 degrees Celsius (from pre-Industrial periods) was unavoidable in the next two decades.

• This would cause greater glacier melt and more water to pour over the steep slopes, resulting in additional landslides.

• The Himalayas are tectonically active mountains formed by the collision of two tectonic plates.

• This increases the likelihood of earthquakes, which might lead to an increase in the number of landslides.

• People Pressure: India accounts for only 2.4 percent of the world's land area yet houses over 17 percent of the world's population.

• Furthermore, the population is expected to expand until 2050, necessitating the construction of more infrastructure in vulnerable environments.

• River Characteristics: The rivers in the Himalayan highlands are huge and in their infancy.

• They perform a lot of downcutting, which increases the likelihood of landslides.

Landslides in India - Natural Causes

• Earthquakes: They induce a sudden shaking of the earth's crust, causing stress on materials and, as a result, landslides.

• Heavy Rainfall: The occurrence of major or continuous rainfall may result in heavy landslides on steep slopes.

• Water acts as a lubricant and loosens the material.

• For example, the 2013 Uttarakhand Cloudburst caused massive landslides in the region.

Landslides in India - Anthropogenic Causes

• Infrastructure Development: The construction of roads, trains, and dams in hilly areas can cause landslides.

• For example, the construction of Konkan Railways in the Western Ghats is regarded as a major cause of the region's frequent landslides.

• Mining is the removal of the earth's surface for mineral discovery, which loosens the material's hold.

• Explosions are also an element of mining, which can cause landslides.

• Deforestation occurs when trees are taken down for agricultural and industrial purposes, causing soil grip to relax and the region to become more prone to landslides.

• Unsustainable Tourism: As the number of tourists increases in the Himalayan area, more infrastructure and services are required to accommodate them.

• This results in more buildings and more landslides.

Consequences of Landslides

• The loss of irreplaceable human and animal life is the most traumatic effect of a landslide.

• Movement is restricted because the mud, boulders, and debris sliding down the hill create a barrier on vital transportation routes such as highways and railway lines.

• Damage to Infrastructure: When a landslide happens, several residences, buildings, roads, and other infrastructure are affected.

• Economic Losses: A considerable amount of money is spent on rebuilding the destroyed infrastructure, rehabilitating the masses, and giving relief assistance to the affected individuals.

• Water Availability May Be jeopardized: When landslides occur on the slopes of a river valley, the sliding mass may reach the valley bottom and produce a partial or total blockage of the river channel.

• This collected mass of avalanche debris that blocks a river is frequently referred to as a landslide dam.

• It may reduce the availability of water for adjacent residents.

Landslide Management in India

• National Risk Management Strategy for Landslides (2019):

• It encompasses all aspects of landslide disaster risk reduction and management, such as hazard mapping, monitoring, and early warning systems, awareness programmed, capacity building, training, regulations, and policies, landslide stabilization and mitigation, and so on.

• Guidelines on Landslide Hazard Management issued by the National Disaster Management Authority (NDMA) in 2009:

• It describes the steps that should be done to minimize or reduce the danger caused by landslide risks. Some pointers –

• Identifying regions prone to landslides

• Encouraging the use of effective landslide rehabilitation and mitigation methods.

• Developing institutional capacity and training for geoscientists, engineers, and planners is essential for efficient landslide management.

• The National Organization of Disaster Management (NIDM) is a prominent institute that provides Capacity Building support to different National and State level authorities in the field of Disaster Management and Disaster Risk Reduction.

• Restriction on building and other development activities such as roads and dams in landslide-prone regions.

• Agriculture is restricted to lowlands and places with modest slopes.

• Control over the growth of big communities in high-vulnerability zones.

• Promoting large-scale afforestation programmed and bund building to minimize water flow.

• Terrace farming should be promoted in the northeastern hill states where Jhumming (Slash and Burn/Shifting Cultivation) is still common.

A Deadly Debris Flow in India

Images of 10 different types of land slides

The United States Geological Survey (USGS) defines a landslide as 'a type of mass wasting event' which involves 'the movement of a mass of rock, debris, or earth down a slope'. As per the latest classification devised by Leroueil and Picarelli (2014), landslides can be categorized under 6 types: Fall, Topple, Slide, Spread, Flow and Slope Deformation.

Figure 1: Illustration of the major types of landslide movement. Source: USGS Publications

References & Resources

USGS publications 

         https://www.atlas-mag.net/en/article/natural-disasters-risk-in-

         india https://www.godigit.com/guides/natural-disasters/types-of-natural-disasters

       ABC News (2021, February 10) Tracing the path of destruction in India’s Himalayas.  

     
 Carbonbrief (2021, February 9) Did climate change contribute to India’s catastrophic ‘glacial flood’?  

     
  The Landslide Blog (2021, February 8) The catastrophic landslide and flood in Chamoli in Uttarakhand: the sequence of events.   

    
    The Landslide Blog (2021, February 15) New perspectives on the Chamoli debris flow disaster.  

       
    The Times of India (2021, February 23) Uttarakhand tragedy: 136 missing to be declared dead. 

      
   Scientific American (2021, February 12) Miniature Satellites Reveal Cause of Deadly Uttarakhand Flood That Devastated Dams.