122 dead as landslides flatten Wayanad villages

The Hindu : Page 01

Syllabus : GS 3 : Geography & Disaster and disaster Management

A devastating series of landslides in Vythiri taluk, Wayanad district, Kerala, killed at least 122 people and injured 197, with the death toll expected to rise.

•  The landslides, originating from a waterlogged hillock, obliterated three villages and altered the course of the Iruvanipuzha river.
•  The Kerala government declared a state of mourning and launched an intense rescue effort with State and Central forces, while bracing for more heavy rain.

About Wayanad

•   Wayanad is the only plateau in Kerala, forming a continuation of the Mysore Plateau, part of the Deccan Plateau.
•   The Kabini River, a tributary of the Kaveri River, originates in Wayanad.
•   The Chaliyar River, the fourth longest river in Kerala, also originates on the Wayanad plateau.
•   Wayanad is home to the Wayanad Wildlife Sanctuary.

Possible reasons behind Wayanad Landslide

•   Heavy rainfall

o  Extremely heavy rainfall, a fragile ecology particularly vulnerable to landslides, and steadily increasing population pressures all combined to trigger multiple landslides.

o  The region received more than 140 mm of rainfall in the 24 hours between the mornings of Monday and Tuesday, about five times more than what is expected.

o  Heavy rains during the monsoon season trigger landslides in Kerala almost every year

•   Hilly terrain with sharp slopes

o  The whole of western Kerala, which is a hilly terrain with sharp slopes, is susceptible to landslides.

o  According to the landslide atlas released by the Indian Space Research Organisation's (ISRO) National Remote Sensing Centre in 2023, 10 out of the 30 most landslide-prone districts in India were located in Kerala, with Wayanad ranked 13th.

o  The terrain here has two distinctive layers, a layer of soil sitting atop hard rocks.

o  When a lot of rain happens, the soil gets saturated with moisture and water reaches the rocks and flows between the soil and the rock layers.

o  This weakens the force that binds the soil to the rocks and triggers the movement.

•   Loss of green cover

o  A 2021 study on landslide hotspots in India revealed that 59 per cent of the total landslides in Kerala occurred in plantation areas.

o  Loss of forests increase the fragility of the terrain, especially in areas prone to heavy rains in the western ghats.

•   Climate change

o  Climate scientists have pointed towards the warming of the Arabian Sea as one of the causes for the extremely heavy and unpredictable rain patterns in the state.

o  The southeast Arabian Sea is becoming warmer, causing the atmosphere above this region, including Kerala, to become thermodynamically unstable.

o  Scientists have noticed a trend of deep cloud systems forming due to the warming of the Arabian sea.

o  This causes extremely heavy spells of rain in shorter periods of time, increasing the risk of landslides, especially when these intrude into land.

•   Environmental neglect and mining

o  Since 2011, the "Western Ghats Ecology Expert Panel" set up by the government under ecologist Madhav Gadgil, has recommended that the Wayanad hill ranges be declared ecologically sensitive.

o  The panel recommended that 75% of the 129,037 sq km area of the mountain range be declared ecologically sensitive because of the presence of dense forests, a large number of endemic species and unique geology.

o  The panel also said that the region needed to be divided into zones based on their ecological sensitivity, where the most vulnerable sections needed to be monitored and protected him from rampant commercial activity.

o  They recommended a ban on mining, quarrying, new thermal power plants, hydropower projects and large-scale wind energy projects in ecologically sensitive zone 1.

o  The suggestions made by the panel have not been implemented even after 14 years due to resistance from state governments, industries and local communities.

Ways to reduce instances of landslides:

•  Afforestation: Planting trees and vegetation to stabilise soil and reduce erosion.
•   Proper Drainage Systems: Installing drainage systems to manage water flow and prevent soil saturation.
•   Slope Reinforcement: Using retaining walls, terracing, and other engineering techniques to stabilise slopes.
•   Regulated Construction: Implementing strict regulations and guidelines for construction activities on slopes.
•  Soil Conservation Practices: Adopting contour plowing, crop rotation, and other soil conservation techniques.
•   Early Warning Systems: Developing and deploying landslide monitoring and early warning systems.
•   Public Awareness: Educating communities about landslide risks and preventive measures.
•   Reforestation: Restoring forests on degraded lands to enhance slope stability.

Key Policy Initiative: National Landslide Susceptibility Map

•   The National Remote Sensing Centre (NRSC) under ISRO released the Landslide Atlas of India in 2023.
•   This detailed guide identifies landslide hotspots across the country with a 100 sq. m resolution overview of landslide susceptibility.
•  The map highlights traditional high-risk areas and uncovers new regions of concern, broadening the scope of landslide monitoring.
•   Scientists conducted a risk assessment based on 80,000 landslides recorded between 1998 and 2022 across 147 districts in 17 states and two Union Territories, creating a “Landslide Atlas” of the country.

Top States by Landslide Events:

•   Mizoram: 12,385 events in the past 25 years.
•   Uttarakhand: 11,219 events.
•   Other states: Kerala, Jammu and Kashmir, Nagaland, Arunachal Pradesh, and Tripura.

Districts with Maximum Landslide Exposure:

•  Arunachal Pradesh: 16 districts.
•   Kerala: 14 districts.
•   Uttarakhand and Jammu and Kashmir: 13 districts each.
•   Himachal Pradesh, Assam, and Maharashtra: 11 districts each.
•  Mizoram: 8 districts.
•   Nagaland: 7 districts

Highest Landslide Density and Risk Exposure:

•   Rudraprayag and Tehri Garhwal districts in Uttarakhand.

 UPSC Mains PYQ : 2021

Ques : Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy.