How to Reduce Landslide Risks

Table of Contents☰

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