UPSC Mains Answer: Differentiate the causes of landslides in the Himalayan region and Western Ghats. (Answer in 150 words)

Difficulty Level: Medium

Sub-category: Geography (Physical Geography - Landforms and Natural Hazards)

---

The Himalayan region and Western Ghats, though both prone to landslides, exhibit distinct causative factors due to their unique geological, climatic, and anthropogenic characteristics.
Himalayan Region: The Himalayas, a young and tectonically active fold mountain range, are highly susceptible to landslides due to their fragile geology. Key causes include: 1. Tectonic Activity: Frequent seismic movements and the collision of the Indian and Eurasian plates destabilize slopes.
2. Steep Slopes and Loose Soil: The region’s youthful topography features steep gradients and unconsolidated debris, prone to sliding.
3. Heavy Rainfall and Glacial Melt: Monsoons and melting glaciers saturate slopes, reducing cohesion and triggering landslides.
4. Anthropogenic Factors: Deforestation, unplanned construction (e.g., roads, dams), and urbanization exacerbate slope instability.
5. Flash Floods: Sudden water surges, often due to cloudbursts, erode slopes and trigger mass movements.
Western Ghats: The Western Ghats, older and more stable, experience landslides primarily due to: 1. Intense Monsoon Rainfall: Prolonged and heavy rainfall saturates lateritic soil, leading to slope failure.
2. Lateritic Soil Composition: The porous, iron-rich soil loses strength when waterlogged, causing landslides.
3. Anthropogenic Pressures: Deforestation for agriculture (e.g., tea, coffee plantations), mining, and infrastructure development weaken slopes.
4. Structural Weaknesses: Fault lines and fractures in the basaltic rock layers create zones of weakness.
5. Urbanization: Unregulated construction, especially in states like Kerala and Karnataka, increases vulnerability.
Conclusion: While tectonic activity dominates landslide triggers in the Himalayas, the Western Ghats are more affected by monsoonal rainfall and human interventions. Mitigation strategies must be region-specific, addressing these distinct causes through sustainable land-use practices and disaster preparedness.