Kerala Faces Recurrent Landslides During the Monsoon

Context

The recent landslides and floods caused by the unusually heavy rainfall in Kerala are an alarming reminder of the growing climate change-related risks and unsustainable developmental activities of the Western Ghats.

Key Highlights

• Landslides occur regularly in the hilly areas of Wayanad, Idukki, Pathanamthitta, Kozhikode and Malappuram areas of Kerala every monsoon. 
• The catastrophic landslides seen in recent years are no longer natural calamities but a result of the combined effect of precariously fragile mountain ecosystems, climate change-induced erratic rainfall patterns, and rising human activities in the Western Ghats. 
• The experience of Kerala emphasizes the need for sustainable development in India to ensure harmonious development between the economic and ecological aspects.

Why is Kerala Highly Prone to Landslides?

• Fragile Geography of the Western Ghats

  • The eastern part of Kerala is part of Western Ghats, which is one of the richest biodiversity hotspots in the world.
  • The slope is steep, the rocks are weathered and the soil is composed of thick layers, which makes the site susceptible to slope failures naturally.
  • When the rain falls for long periods of time, water drains into the soil and pools between the surface soil and the underlying hard rock.
  • Once this layer fills up, the soil loses its hold, leading to whole stretches of hillsides falling away.

• Intense and Prolonged Monsoon Rainfall

  • Southwest Monsoon contributes a significant percentage to the rainfall in Kerala.
  • This continual rain causes the soil to become saturated, and a few hours of heavy rain cause tremendous pressure.
  • Even a few hours of heavy rain can cause great landslides once the soil is saturated.

• Rising Effect of Climate Change

  • According to scientific studies, the frequency of short spells of heavy rain has been observed to have increased in the Western Ghats due to climate change.
  • The changing climatic conditions are also affecting the monsoons, which is making rainfall more extreme and unpredictable.
  • This means that the chances of flash floods, landslides and debris flows are increasing on an annual basis.

Human Activities Making the Situation Worse

• Though heavy rainfall is the immediate trigger, the vulnerability of the hill slopes of Kerala has been enhanced by human activities to a great extent.
• Deforestation and Plantation Expansion
  • Significant areas of primary forest have been taken over by tea, coffee and rubber plantations.
  • Native trees have deep and extensive root systems which secure the soil.
  • Shallow rooting of plantation crops generally results in shallower rooting of the slopes, which makes them less resistant to heavy rain.
• Quarrying and Mining
  • Uncontrolled quarrying reduces the stability of rock structures and affects natural hillside stability.
  • Fractures are formed by blasting and excavation, which can be opened up by heavy rainfall.
• Road Construction and Urbanisation
  • Road, tourist, and housing developments cut into the hillside and change the natural slope.
  • Rainwater is not allowed to drain freely due to poor planning and leads to increased slope instability.
• Encroachment into Ecologically Sensitive Areas
  • More people and infrastructure in vulnerable hill regions will be exposed to landslide hazard due to increasing settlements.
  • Geological assessment and hazard mapping are often not done in development.

Why These Landslides Matter

• Human Cost
  • Landslides result in injuries, loss of life and house damage.
  • Rescue and rehabilitation are very difficult in a remote hilly area.
• Economic Impact
  • Roads and bridges are severely damaged, as are electricity and communication lines.
  • Agriculture, tourism and local livelihood activities suffer badly.
• Environmental Consequences
  • Use of valuable forest cover is lost.
  • Loss of soil by erosion decreases the productivity of agriculture.
  • Rivers become much silted and the chances of flooding downstream are higher.
  • The Western Ghats wildlife habitats are permanently damaged.

Government Initiatives

• In India, several steps have been taken to minimize the risks of landslides:
• National Landslide Risk Management Strategy (2019) for hazard assessment and mitigation.
• Guidelines on Landslide Management for preparedness and response by NDM.
• The sophisticated weather forecasting and rainfall warnings facility of IMD.
• Geological Survey of India (GSI) Landslides Susceptibility Mapping.
• ISRO’s Landslide Atlas for determination of vulnerable areas.
• Utilisation of NDRF & SDRF in emergencies.

Challenges Ahead

• Precipitation is becoming more erratic as a result of climate change.
• Government policies are poorly enforced.
• Quarrying and building still take place in the areas that are at risk.
• Maps of hazard zones in the majority do not always form part of the local planning process.
• Public awareness on landslide risk remains low.

Way Forward

• Use scientific land-use planning using landslide susceptibility maps.
• Control and monitor quarrying, mining, and construction in ecologically sensitive areas.
• Rehabilitation of degraded forests – plantation of native trees.
• Boost early warning systems with the help of satellite technology, artificial intelligence and real-time rainfall monitoring.
• Encourage community disaster preparedness and frequent evacuations.
• Make climate resilience a component of Infrastructure Planning and District Development Plans.
• Put into practice the recommendations of the Sendai Framework for Disaster Risk Reduction (2015-2030) and enhance ecosystem-based disaster risk reduction.

Source: The Indian Express

Mains PYQ

Q. Differentiate the causes of landslides in the Himalayan region and Western Ghats. (2021)

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