How to Reduce Landslide Risks

What’s in today’s article?

• Why in News?
• Possible Causes of Landslide in Wayanad
• Landslides Prevention Techniques/ Measures

Why in News?

• Massive landslides hit the district of Wayanad in northern Kerala, triggering large-scale death (toll stands at 215) and destruction and the number of missing people indicate that the real toll will be higher.

Possible Causes of Landslide in Wayanad:

• Natural:
  • According to the Geological Survey of India (GSI), almost half of Kerala’s land area is prone to landslides.
  • The heavy rainfall in the region and the slope of the Western Ghats means that 31.54% of the Wayanad district is highly susceptible to landslides.
• Anthropogenic:
  • Increasing construction activities:
    • The Wayanad region has become a tourist hotspot, with homestays and monsoon tourism being the latest trends.
    • The construction of resorts, artificial lakes and quarrying activities in the eco-sensitive zones (ESZ) have exacerbated the danger of a landslide.
  • Changes in crop patterns:
    • Land use changes have occurred starting with the British-era tea plantations.
    • In Wayanad, there has been a 62% reduction in forest cover between 1950 and 2018, coupled with a 1,800% increase in the area under plantation.
    • Such monocropping leads to a loosening of the topsoil that was once held in place by the roots of a forest.
  • Climate change:
    • Climate change has played an indirect role, leading to changes in rainfall patterns in the State.
    • The warming of the Arabian Sea is allowing the formation of deep cloud systems, leading to extremely heavy rainfall over a shorter period. Heavy rainfalls cause run-offs that can lead to landslides.
  • Issues with landslide warnings:
    • The IMD issues warnings for heavy rainfall (in a colour-coded system) and the week before the landslides, the alert was largely yellow, which does not call for action.
    • The GSI has been designated the nodal agency for landslide studies, and has been given the responsibility of evolving an early warning system and protocols for landslide risk reduction.
    • However, this is still in the experimental stage and will take four or five more years to be ready for public use, a senior GSI official said.

Landslides Prevention Techniques/ Measures:

• Banning/ regulating construction activities in ESZ: For example, the Gadgil panel report of 2011 recommended that the entire region of the Western Ghats, spanning 1,29,000 square km across six States, be declared an ESZ.
• Upgrading institutional capacities and coordination: For example, IMD must use new technologies for accurate weather predictions.
• Engineering solutions:
  • Slope stabilisation: It involves adding structural elements to the slope to increase its stability.
  • Grading and terracing: It involves modifying the slope’s shape and gradient to reduce the risk of landslides.
  • Soil reinforcement: It involves adding materials to the slope to increase its strength and stability.
• Natural solutions:
  • Vegetation control: Planting trees, shrubs, or grasses can help stabilise the soil, absorb excess water, and reduce erosion.
  • Mulching: Mulch is a layer of organic or inorganic material applied to the soil surface. It helps retain moisture, prevent erosion, and stabilise the slope.
  • Bioengineering techniques: They combine the use of plants and engineering principles to stabilise slopes.
  • Water management: It slows down the flow of water, allowing it to infiltrate the soil gradually.
• Early warning systems and monitoring for landslides: They provide timely information and alerts, allowing individuals and communities to take necessary actions to mitigate the impacts of landslides.
• Emergency preparedness for landslides: Despite preventive measures, landslides can still occur. Being prepared and knowing how to respond during a landslide event is crucial for minimising the risks.

Q.1 What is the Geological Survey of India (GSI)?

The GSI is a scientific agency of India founded in 1851 as a Government of India organisation under the Ministry of Mines. It is one of the oldest organisations conducting geological surveys and studies of India.

Q.2. How are eco-sensitive zones (ESZ) declared in India?

In order to manage and conserve biodiversity across the Protected Areas (PAs), the Ministry of Environment, Forest and Climate Change notifies Eco-Sensitive Zones (ESZs) around the PAs.

Source: Questions beyond Wayanad, spilled across the country

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