A fresh landslide disaster has struck the Eastern Himalayas, this time in North Sikkim, impacting the Chaten region near the Lachen River. The incident led to the loss of army personnel and damage to military camps, raising serious questions about Himalayan fragility, climate extremes, and unplanned development.
What this really highlights is not just a local disaster, but a systemic vulnerability of Himalayan states, especially Sikkim and Uttarakhand.
Let’s break it down the way UPSC expects.
Contents
- 1 What is the Lachen River and Why Is This Region Sensitive?
- 2 Geological Setting of the Chaten–Lachen Region
- 3 Why Are Landslides More Frequent in Sikkim?
- 4 Link with Past Disasters: GLOF Events in Sikkim
- 5 Why Uttarakhand and Sikkim Report More Landslides Than Himachal Pradesh?
- 6 Core UPSC Takeaway
- 7 Check out our GS Geography Course – Click Here
- 8 FAQs
What is the Lachen River and Why Is This Region Sensitive?
The Lachen River is part of the larger Teesta River basin, one of the most dynamic river systems in the Eastern Himalayas.
Key tributaries and source streams include:
- Lachen River
- Lachung River
- Rangit River
- Rangpo River
All of them drain steep Himalayan terrain in North Sikkim, an area dense with:
- Multiple watersheds
- Small seasonal streams
- Glacial and snow-fed channels
This dense drainage network increases slope saturation, especially during intense rainfall events.
Geological Setting of the Chaten–Lachen Region
The Chaten region lies in a geologically young and unstable zone of the Eastern Himalayas.
Important geological characteristics:
- Dominance of soft sedimentary rocks
- High degree of weathering
- Steep valley slopes
- Thin soil cover over fractured bedrock
Such formations are inherently landslide-prone, even without human interference.
Why Are Landslides More Frequent in Sikkim?
1. Extremely Steep Eastern Himalayas
The Eastern Himalayas are generally steeper than the Western Himalayas (Himachal and Uttarakhand), increasing gravitational stress on slopes.
2. High Rainfall and Cloudbursts
Sikkim, along with Arunachal Pradesh and Assam Himalayas, receives:
- Very high annual rainfall
- Increasing cloudburst events due to climate change
Sudden cloudbursts rapidly saturate slopes, triggering mass movements.
3. Climate Change Impact
Global warming has intensified:
- Short-duration, high-intensity rainfall
- Glacial melt and unstable moraine zones
This directly raises landslide and flood risks.
4. Rising Construction and Deforestation
Recent years have seen:
- Road widening
- Tourism infrastructure
- Military and hydropower-related construction
These activities disturb slope equilibrium and accelerate erosion.
Link with Past Disasters: GLOF Events in Sikkim
Sikkim has already experienced Glacial Lake Outburst Floods (GLOFs), notably linked to the Lhonak Glacier system.
These events:
- Washed away bridges and settlements
- Severely damaged Teesta basin infrastructure
- Exposed the risks of glacially influenced river systems
The recent Chaten landslide fits into this broader pattern of cryosphere-driven disasters.
Why Uttarakhand and Sikkim Report More Landslides Than Himachal Pradesh?
This is a common UPSC comparison area.
Uttarakhand and Sikkim
- Highly tectonically active zones
- Presence of major thrusts like:
- Main Boundary Thrust (MBT)
- Main Central Thrust (MCT)
- Extensive:
- Dam construction
- Tunneling
- River diversion projects
- Road expansion (e.g., Char Dham Project)
Himachal Pradesh (Comparatively)
- Fewer new mega dam projects
- Large northern areas (Lahaul–Spiti) are:
- Sparsely populated
- Low in construction activity
- Landslides exist (Shimla, Kinnaur, Mandi), but frequency is lower overall
The takeaway: human pressure + tectonic sensitivity = disaster amplification.
Core UPSC Takeaway
The Sikkim landslide is not an isolated event. It reflects:
- Fragile Himalayan geology
- Climate change–driven extreme rainfall
- Unregulated development in sensitive zones
For UPSC, this case is relevant across:
- GS I: Geomorphology, Natural Hazards
- GS III: Disaster Management, Climate Change, Infrastructure
Check out our GS Geography Course – Click Here
FAQs
- #SikkimLandslideUPSC: Why are landslides frequent in Sikkim Himalayas?
- #LachenRiverTeestaBasin: What is the significance of the Lachen River in the Teesta basin?
- #EasternHimalayasGeology: Why are the Eastern Himalayas more landslide-prone than the Western Himalayas?
- #HimalayanDisasterManagement: How do climate change and development increase landslide risks in Himalayan states?
