Model Answer
0 min readIntroduction
Landslides are a common geological hazard in India, particularly in the mountainous regions. While both the Himalayas and the Western Ghats experience landslides, the frequency and scale are significantly higher in the Himalayas. This disparity isn’t accidental; it stems from fundamental differences in their geological formations, topographical characteristics, climatic conditions, and human activities. Recent events like the 2021 Chamoli disaster in Uttarakhand underscore the vulnerability of the Himalayan region to such events, prompting a need to understand the underlying causes for this increased susceptibility.
Geological and Topographical Factors
The Himalayas are geologically younger and more fragile compared to the Western Ghats. They are formed by the collision of the Indian and Eurasian plates, resulting in highly folded, faulted, and fractured rock formations. This makes the slopes inherently unstable.
- Himalayas: Predominantly composed of sedimentary and metamorphic rocks, with significant presence of loose sediments (moraines, glacial deposits). Active tectonic activity continues to shape the landscape, increasing instability. Steep slopes and high relief are characteristic.
- Western Ghats: Primarily composed of hard, crystalline rocks (granite, basalt) which are more resistant to erosion and weathering. Geologically older and more stable. Slopes are generally less steep than in the Himalayas.
Climatic Influences
Climatic conditions play a crucial role in triggering landslides. The Himalayas experience more intense rainfall and prolonged periods of snowmelt, saturating the slopes and increasing pore water pressure.
- Himalayas: Monsoon rainfall is exceptionally heavy, often exceeding 4000mm annually in some areas. Rapid snowmelt during spring and summer further contributes to slope instability. Frequent cloudbursts exacerbate the situation.
- Western Ghats: Receives heavy rainfall, particularly on the windward side, but generally less intense and prolonged than in the Himalayas. Rainfall patterns are more predictable.
Anthropogenic Activities
Human activities exacerbate landslide risk in both regions, but the scale and nature of these activities differ.
- Himalayas: Large-scale infrastructure development (roads, dams, hydropower projects) often involves slope cutting and blasting, destabilizing the terrain. Deforestation for agriculture and settlements further reduces slope stability. Unplanned urbanization and tourism contribute to the problem.
- Western Ghats: Deforestation for plantations (tea, coffee, rubber) and quarrying are major concerns. However, infrastructure development is generally less extensive than in the Himalayas.
Comparative Table
| Feature | Himalayas | Western Ghats |
|---|---|---|
| Geological Age | Young, actively forming | Old, stable |
| Rock Type | Sedimentary, metamorphic, loose sediments | Crystalline (granite, basalt) |
| Tectonic Activity | High | Low |
| Rainfall Intensity | Very High, prolonged | High, but less prolonged |
| Slope Steepness | Very Steep | Moderate |
| Infrastructure Development | Extensive | Moderate |
Role of Glacial Activity
Glacial retreat in the Himalayas, linked to climate change, is creating unstable slopes and increasing the risk of glacial lake outburst floods (GLOFs), which can trigger landslides.
Conclusion
In conclusion, the higher frequency of landslides in the Himalayas compared to the Western Ghats is primarily attributable to the region’s young and fragile geology, intense rainfall, active tectonic activity, and extensive anthropogenic pressures. While the Western Ghats are also susceptible to landslides, the inherent stability of its rock formations and comparatively less intense climatic and human impacts contribute to a lower overall risk. Sustainable land use planning, robust infrastructure development practices, and effective disaster management strategies are crucial for mitigating landslide hazards in both regions, but particularly vital in the vulnerable Himalayan landscape.
Answer Length
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