Introduction

In response to the catastrophic landslides that struck Wayanad on July 30, an expert panel led by John Mathai, former scientist of the National Centre for Earth Science Studies (NCESS), has made critical recommendations to mitigate the risk of future landslides in the region. The panel’s report highlights the urgent need for habitat-free zones in landslide-susceptible areas, calls for curbs on construction, and recommends bioengineering solutions to stabilize affected regions. This article delves into the findings of the report, explores the underlying causes of the landslides, and evaluates the long-term sustainability measures suggested by the expert committee.

The Wayanad Landslide: A Devastating Event

Wayanad, located in the Western Ghats, is known for its stunning landscapes and lush green slopes. However, the region’s susceptibility to landslides has raised alarm in recent years. On July 30, a massive landslide swept through Mundakkai-Chooralmala, causing widespread destruction. The total area affected was 107.5 hectares, with 104 hectares directly impacted by the landslide. Massive volumes of soil and debris, estimated at 25 lakh cubic meters, were displaced from the crown to the base of the slope, leaving a trail of devastation. Schools, roads, and homes lay in the path of destruction, underscoring the critical need for preventive measures.

The Expert Panel’s Recommendations

The panel, constituted in August 2024, undertook a comprehensive study titled “Mundakkai - Chooralmala Landslide, Wayanad district: A Comprehensive Study,” to assess the causes and suggest solutions. Their findings were presented in a September 25-dated report, which emphasized several key recommendations.

1. Habitat-Free Zones in Unsafe Areas

The committee’s foremost recommendation is to demarcate unsafe zones and keep them free of human habitation. This includes the 107.5 hectares identified as vulnerable, with particular attention to the areas directly impacted by the landslide. The report emphasizes that no residential or commercial structures should be allowed in these zones to minimize the risk to human life.

2. Regulating Construction Activities

The report advocates for strict regulation of construction and other human interventions in landslide-prone areas. It suggests banning activities that could trigger further soil instability, such as road construction on unstable slopes, leveling slopes for construction, and quarrying near susceptible areas.

3. Prohibiting Specific Agricultural Practices

The panel also highlighted the role of certain agricultural activities in exacerbating landslide risks. Practices like contour bunding and terracing on slopes steeper than 25%, seasonal cultivation with tilling in high-sloping areas, and encroachment on stream banks should be discouraged, as they contribute to soil saturation and instability.

4. The Role of Bioengineering in Slope Stabilization

A significant recommendation involves the use of bioengineering techniques to stabilize landslide-affected regions. Planting wild reeds, vetiver grass, and indigenous trees, alongside wattling and coir geotextiles, can help prevent further erosion and degradation. These techniques can not only restore ecological balance but also serve as long-term preventive measures.

The Role of Excess Rainfall

While landslides in the Western Ghats are often linked to human activity, the committee ruled out the presence of quarries as a triggering agent for the July 30 landslide. Instead, it pointed to the excessive rainfall that occurred during that period. With more than 50 mm of rainfall per hour in continuous heavy spells, the already saturated soil gave way, leading to the landslide. Converging streams funneling stormwater to the hollow regions further aggravated the situation.

Micro-Zonation Studies: A Vital Step Forward

One of the most critical aspects of the panel’s recommendations is the call for micro-zonation studies. These studies would involve detailed mapping of landslide-susceptible zones on a cadastral scale. By identifying potential failure points and documenting their run-out paths, local authorities can better prepare for future disasters. These studies should be shared with local communities to enhance awareness and preparedness.

Curbing Anthropogenic Activities

Anthropogenic activities, such as blasting and quarrying near vulnerable areas, should be strictly regulated, the report notes. These activities weaken slope stability and increase the risk of landslides. Even minor human interventions like constructing swimming pools or theme parks in high-hazard zones should be avoided. The report calls for strict guidelines to regulate tourism-related activities, which often disrupt the natural balance in sensitive areas.

Agricultural and Soil Conservation Practices

In addition to construction, agricultural practices also play a significant role in influencing soil stability. The report discourages practices such as contour bunding, terracing on steep slopes, and encroachment on stream banks. These practices, while beneficial for certain types of farming, increase soil saturation and weaken slope integrity in landslide-prone regions.

The Punnapuzha River: Addressing Degradation

The landslide also caused significant damage to the Punnapuzha River, with large boulders being deposited in the riverbed. To prevent further scouring and degradation of the river, the panel recommends moving these boulders to the riverbank. This will allow the river to accommodate floodwaters and debris without disrupting the natural flow. The panel also suggests surveying the new boundaries of the river and maintaining records to prevent future encroachment or human interference.

Long-Term Solutions: Balancing Development and Environmental Conservation

The recommendations from the expert panel underscore the need for a balanced approach to development and environmental conservation in Wayanad. While human settlements and agricultural activities are vital for the local economy, the region’s vulnerability to landslides necessitates stricter regulations. By implementing habitat-free zones, regulating construction, and adopting sustainable agricultural practices, authorities can reduce the risk of future disasters.

The Importance of Community Awareness and Involvement

A key aspect of mitigating landslide risks is increasing community awareness. The panel stresses the need for local authorities to educate communities about landslide-prone areas and the importance of adhering to regulations. Involving communities in micro-zonation studies and disaster preparedness plans can enhance resilience and ensure a swift response in the event of future landslides.

Conclusion: A Path to a Safer Future for Wayanad

The Wayanad landslides serve as a grim reminder of the devastating power of natural disasters, especially in ecologically sensitive regions. The expert panel’s comprehensive study offers a roadmap for reducing the risk of future landslides through habitat-free zones, sustainable practices, and bioengineering solutions. By implementing these recommendations, authorities can protect both human lives and the environment, ensuring a safer future for Wayanad’s residents.

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References:

1. National Centre for Earth Science Studies (NCESS) Report (2024) - Mundakkai - Chooralmala Landslide: A Comprehensive Study
2. Kerala State Disaster Management Authority (KSDMA) - Expert Committee Findings on Wayanad Landslide (2024)
3. Kerala State Soil Conservation Department (2024) - Landslide Impact and Bioengineering Solutions for Western Ghats
4. Pradeep G.S., Hazard and Risk Analyst, Kerala State Disaster Management Authority - Landslide Risk Mitigation Strategies
5. Local Media Reports on Wayanad Landslide (2024) - Public Engagement and Disaster Awareness in Wayanad District