Landslides In Wayanad:
The Wayanad district of Kerala has witnessed one of the most devastating landslide-related disasters due to extreme rainfall and fragile ecological conditions.
- The district received over 140 mm of rain in 24 hours, surpassing expectations and recalling the devastating 2018 floods that claimed around 500 lives.
- A landslide is the downward movement of rock, soil, and debris on a slope, ranging from small shifts to large, destructive events.
- It can occur on natural or man-made slopes and is triggered by factors like heavy rainfall, earthquakes, volcanic activity, human activities, and changes in groundwater levels.
- As per the Geological Survey of India, the economic loss due to landslides may amount to as much as 1% to 2% of the Gross National Product (GNP) in many developing countries
Causes of Landslides:
- Gravitational Forces: These are the primary cause of landslides, constantly pulling materials on slopes downward.
- Rainfall: Prolonged or intense rainfall increases soil water content, reducing cohesion and adding weight to slopes, making them more prone to failure.
- Earthquakes: Earthquakes destabilise slopes by shaking the ground and weakening the structural integrity of geomaterials, especially in tectonically active regions like the Himalayas.
- Erosion: Natural processes such as river or wave action can erode the base of slopes, undermining their stability. Coastal areas are particularly susceptible to landslides due to wave-induced erosion.
- Hydrological Factors: Groundwater movement can contribute to landslide risk. Water can seep through porous materials, increasing pore pressure and reducing effective stress, thereby weakening the slope.
