Bring out the causes for more frequent landslides in the Himalayas than in Western Ghats
Introduction
Landslides are a common natural hazard in India, particularly in mountainous regions like the Himalayas and the Western Ghats. However, the Himalayas experience more frequent landslides due to a combination of geological, climatic, and anthropogenic factors. According to the Geological Survey of India, nearly 15% of India’s land area is prone to landslides, with the Himalayas being the most vulnerable.
Key Differences at a Glance
| Factor | Himalayas | Western Ghats |
|---|---|---|
| Geological Structure | Young, tectonically active mountains | Older, stable block mountains |
| Slope Steepness | Steeper slopes | Relatively gentler slopes |
| Rainfall Pattern | Intense monsoonal and glacial melt | Heavy but seasonal monsoonal rains |
| Human Activity | Extensive deforestation, road cutting | Limited but increasing human activity |
Causes for More Frequent Landslides in the Himalayas
1. Geological Factors
- The Himalayas are geologically young (formed ~50 million years ago) and tectonically active due to the ongoing collision of the Indian and Eurasian plates. This results in unstable rock formations and frequent seismic activity, which trigger landslides.
- In contrast, the Western Ghats are older and more stable, with less tectonic activity.
2. Topography and Slope
- The Himalayas have steeper slopes and higher altitudes, making them more prone to landslides. The steep gradient increases the gravitational pull on loose soil and rocks.
- The Western Ghats have gentler slopes, reducing the likelihood of large-scale landslides.
3. Climatic Conditions
- The Himalayas experience intense monsoonal rainfall and glacial melt, which saturate the soil and weaken its stability. Additionally, cloudbursts are more frequent in the region, causing sudden and massive landslides.
- The Western Ghats, while receiving heavy rainfall, do not face glacial melt or cloudbursts as frequently.
4. Anthropogenic Activities
- The Himalayas are subject to extensive deforestation, unplanned urbanization, and infrastructure development (e.g., road construction, hydropower projects). These activities destabilize slopes and increase landslide frequency.
- The Western Ghats, though affected by deforestation and quarrying, face relatively less human-induced pressure.
5. Soil and Vegetation
- The Himalayas have loose, unconsolidated soil due to their young geological age, which is easily eroded. Sparse vegetation in higher altitudes further exacerbates soil erosion.
- The Western Ghats have lateritic soil and dense forest cover, which provide better slope stability.
Conclusion
The Himalayas’ geological youth, steep slopes, intense rainfall, and human activities make them more prone to landslides compared to the Western Ghats, which are older, more stable, and less disturbed. Addressing these vulnerabilities requires sustainable development practices, afforestation, and improved early warning systems to mitigate the impact of landslides.