Himalaya–Karakoram Glacial Flood Risks Poorly Assessed: Study Warns
Table of Contents
Relevance:
GS Paper III – Environment, Climate Change, Disaster Management
Important Keywords
For Prelims:
- Glacial Lake Outburst Flood (GLOF), Himalaya–Karakoram Region, Moraine-Dammed Lakes, Ice-Dammed Lakes, Supraglacial Lakes, Elevation-Dependent Warming, Glacier Retreat, Cryosphere, Third Pole, Flash Floods, Early Warning Systems (EWS)
For Mains:
- Climate Change and Mountain Hazards, Himalayan Ecology, Disaster Risk Reduction (DRR), Climate-Induced Disasters, Vulnerability of Mountain Communities, Cryosphere Monitoring, Adaptation and Resilience, Role of Remote Sensing, Transboundary Disaster Risks, Sustainable Development in Himalayan Region
Why in News?
A recent study published in npj Natural Hazards (January 2026) warns that glacial lake outburst flood (GLOF) risks in the Himalaya–Karakoram region are poorly assessed and weakly monitored, despite rapid climate-driven expansion of glacial lakes. Nearly one million people living downstream face potential flood threats due to inadequate research, monitoring and early-warning systems.
What are Glacial Lake Outburst Floods (GLOFs)?
A Glacial Lake Outburst Flood (GLOF) occurs when a natural dam holding a glacial lake collapses, releasing a sudden surge of water downstream.
- These floods often carry debris, rocks, soil and ice, amplifying destruction.
- Types of glacial lakes:
- Moraine-dammed lakes – blocked by loose rock and debris.
- Ice-dammed lakes – restrained primarily by ice.
- Supraglacial lakes – form on glacier surfaces and can drain suddenly during rapid melting.
Rising GLOF Events in the Himalaya–Karakoram Region
The study documents 388 GLOF events across the region so far:
- Karakoram: 196 events
- Central Himalayas: 99 events
- Eastern Himalayas: 72 events
- Western Himalayas: 21 events
By lake type:
- Moraine-dammed lakes: 163 events
- Ice-dammed lakes: 144 events
- Supraglacial lakes: ~50 events
By country:
- Pakistan: 131 events
- China: 123 events
- India: 59 events
- Nepal: 54 events
India’s Experience with GLOFs
India has witnessed some of the deadliest GLOF disasters:
- Uttarakhand (2013): Failure of the Chorabari glacial lake triggered floods and landslides, killing nearly 5,000 people.
- Sikkim (2023): Collapse of a glacial lake wall killed 55 people and caused massive infrastructure damage.
These events highlight India’s high vulnerability to glacial hazards.
Climate Change, Warming and Expanding Glacial Lakes
Climate change is intensifying GLOF risks due to elevation-dependent warming, where higher altitudes warm faster.
Since 1990:
- Number of glacial lakes increased by 53%
- Total lake area increased by 51%
- Total lake volume increased by 48%
Glaciers ending in lakes are retreating faster than land-terminating glaciers, creating a feedback loop that accelerates lake growth and instability.
Research Gaps and Monitoring Deficiencies
Despite rising risks, research and preparedness have not kept pace:
- Limited social vulnerability assessments for downstream communities.
- Inadequate studies on future GLOF frequency under climate change.
- Poor coverage of early-warning systems (EWS).
- Heavy reliance on remote sensing, with limited ground-based observations.
- Lack of standardised definitions and size thresholds for glacial lakes.
- Most datasets are static, failing to capture seasonal changes, rapid lake evolution and short-lived but dangerous lakes.
These gaps reduce the effectiveness of risk assessment and disaster preparedness.
Why the Himalayas are Hard to Study
- Rugged terrain and harsh climate restrict field-based research.
- Satellite data often suffers from coarse spatial and temporal resolution.
- Variations in lake classification (moraine, supraglacial, ice-contact) lead to inconsistent datasets across regions.
Way Forward
- Develop region-specific, integrated GLOF risk assessments.
- Strengthen ground-based monitoring and high-resolution mapping.
- Expand early-warning systems and disaster preparedness in vulnerable areas.
- Incorporate social vulnerability and community-based adaptation.
- Improve cross-border cooperation in the Himalaya–Karakoram region.
Conclusion
The Himalaya–Karakoram region is entering a phase of heightened glacial flood risk due to climate change, expanding glacial lakes and insufficient monitoring. Without urgent improvements in research, data integration and early-warning mechanisms, GLOFs could become one of the most dangerous climate-induced disasters for mountain communities in South Asia.
UPSC PYQ
Q. ISRO, in its studies, has revealed that there is a 178% increase in the size of the Ghepang Ghat Glacial Lake. In which of the following States/UTs is this lake located? (CDS-II/2024)
- Jammu & Kashmir
- Ladakh
- Himachal Pradesh
- Uttarakhand
Answer: C
Explanation:
- Ghepang Ghat Glacial Lake is located in the Lahaul and Spiti district of Himachal Pradesh, at an elevation of around 4,068 metres.
- ISRO and NRSC satellite-based studies show that the lake expanded by 178%, from 36.49 hectares (1989) to 101.30 hectares (2022).
- The expansion is driven by glacial retreat and accelerated melting in the Indus River Basin.
- Such rapid growth significantly increases the risk of Glacial Lake Outburst Floods (GLOFs), threatening downstream settlements and infrastructure.
CARE MCQ
Q.With reference to Glacial Lake Outburst Floods (GLOFs) and Lake Outburst Floods (LOFs), consider the following factors:
- Large volume of water stored in moraine-dammed glacial lakes.
- Narrow and high moraine dams with limited freeboard.
- Presence of stagnant glacier ice within the moraine dam.
- Avalanche displacement waves caused by calving glaciers, rockfalls and hanging glaciers.
- Catastrophic drainage of water into the lake from sub-glacial, englacial or supraglacial channels.
Which of the above contribute to the occurrence of glacial lake outburst hazards?
- 1, 2 and 3 only
- 1, 2, 3 and 4 only
- 2, 3, 4 and 5 only
- 1, 2, 3, 4 and 5
Answer: D
Explanation:
- Statement 1 – Correct:
Larger lake volume increases hydrostatic pressure on the moraine dam, raising failure risk. - Statement 2 – Correct:
Narrow, steep moraine dams with low freeboard are structurally unstable and prone to overtopping. - Statement 3 – Correct:
Stagnant ice within moraine dams can melt internally, weakening dam integrity. - Statement 4 – Correct:
Avalanches, glacier calving, and rockfalls generate displacement waves that can overtop or breach the dam. - Statement 5 – Correct:
Sudden inflow from sub-glacial, englacial or supraglacial channels can rapidly raise lake levels, triggering outbursts.
