Intro:
Landslides are mass movements of rock, debris, or earth down a slope. Both the Himalayas and Western Ghats are landslide-prone but differ in geological origin, structure, and triggers.
1. Geological Structure:
- Himalayas:
- Young Fold Mountains – tectonically active.
- Highly fragile rocks, steep slopes.
- Ongoing orogeny causes faulting, fracturing.
- Western Ghats:
- Old block mountains, tectonically stable.
- Composed of hard basaltic rock (Deccan Traps).
- Lesser natural instability than Himalayas.
2. Seismic Activity:
- Himalayas:
- High seismicity (Zone V), frequent earthquakes cause slope weakening.
- Western Ghats:
- Low seismic activity, fewer earthquake-induced landslides.
3. Rainfall & Climate:
- Himalayas:
- Snowmelt + monsoon rain causes saturation and slope failure.
- High altitude regions vulnerable during cloudbursts.
- Western Ghats:
- Heavy monsoonal rain (2000–7000 mm annually).
- Landslides mostly during July–September due to slope saturation.
4. Anthropogenic Factors:
- Himalayas:
- Road cutting on steep slopes (e.g., Char Dham Project).
- Hydroelectric projects, deforestation.
- Western Ghats:
- Quarrying, slope modification for tourism.
- Plantation agriculture increases surface runoff.
5. Vegetation Cover:
- Himalayas:
- Sparse vegetation at higher altitudes.
- Increased soil erosion and debris flow.
- Western Ghats:
- Thick forests in natural state.
- Deforestation for crops increases vulnerability.
Conclusion:
Landslides in the Himalayas are primarily due to tectonic instability and seismicity, while in the Western Ghats, they are rainfall-induced and human-triggered. Region-specific mitigation strategies are essential.
