A massive glacier burst at Chamoli in Uttarakhand has yet again brought back our focus to the dangers of climate change. At least 58 people are confirmed to have been killed and more than 150 are missing.
Background
- The flash flood began on 7 February 2021 in the environs of the Nanda Devi National Park in the outer Garhwal Himalayas in Uttarakhand.
- It is believed to have been caused by a landslide, an avalanche or a glacial lake outburst flood.
- It has caused flooding in the Chamoli district, most notably in the Rishiganga River, the Dhauliganga River, and in turn the Alaknanda the major headstream of the Ganges.
What has happened in Chamoli?
- Experts are uncertain about what caused the massive Glacial Lake Outburst Flood at Chamoli in Uttarakhand.
- It is unclear whether there was an avalanche in the area recently or whether the lake breach was the result of construction, anthropological activities, climate change etc.
A GLOF or glacial lake outburst flood is suspected. However, the paradox is that this region of the Himalayas does not have any known glacier lakes. However, if it was indeed a GLOF, the question of where the glacier lake is still holding.
What is Glacial Lake Outburst Flood (GLOF)?
- A GLOF is a type of outburst flood that occurs when the dam containing a glacial lake fails.
- An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a jökulhlaup.
- The dam can consist of glacier ice or a terminal moraine.
- Failure can happen due to various factors such as:
- Erosion, a buildup of water pressure
- Avalanche of rock or heavy snow
- Earthquake or volcanic eruptions under the ice or
- Displacement of water in a glacial lake when a large portion of an adjacent glacier collapses into it
Possible causes
(A) Avalanche
- An avalanche is falling masses of snow and ice which gathers pace as it comes down the slope.
- It is often caused by erosion or small tremors of earthquakes.
- But an avalanche is unlikely to result in the rise of water of that magnitude what Chamoli witnessed.
(B) Cloudburst
- What happened in Uttarakhand in 2013 was a multi-day cloudburst.
- It is a sudden, very heavy rainfall accompanies by a thunderstorm. But it generally happens in monsoon.
- In fact, the season in which such a disaster was witnessed has surprised experts as there is no immediate trigger that can be pointed to as the reason why water level rose to that level washing away two hydro projects.
(C) Water pockets
- Satellite images do not show a glacial lake near the region, but there’s a possibility there may be a water pocket in the region.
- Water pockets are lakes inside the glaciers, which may have erupted leading to this event.
Uttarakhand is the birthplace of India’s environmental consciousness as this is where the women stopped the felling of trees in the Chipko Movement.
Why is Uttarakhand so vulnerable to the disasters?
(A) Mystery lies covered under the glaciers
- There are over 1,000 glaciers in Uttarakhand. Almost all of them are receding. Most of the glaciers also have debris cover.
- When glaciers retreat due to rising temperatures, the snow melts but the debris remains. This debris aids in the formation of lakes.
Cause: Retreat of glaciers
- Glaciers have reduced considerably in mass and surface area since the little ice age period.
- This has led to the formation of a large number of glacial lakes all across the Himalayas.
- Many of these high-altitude lakes are potentially dangerous, because of their potential to cause flash floods in the event of a breach.
(B) Topography
- Uttarakhand is located in the midst of young and unstable mountains and is subject to intense rainfall.
- Over the years, the frequency of formation of these lakes has increased.
(C) Seismic activities
- The Himalayas are the world’s youngest mountain ranges, prone to erosion and landslides and unstable because of high seismic activity.
- The current policy of the government of pursuing hydro-power projects indiscriminately cannot be ignored.
- The entire State of Uttarakhand is categorised as falling in Zone-IV and V of the earthquake risk map of India.
(D) Anthropogenic causes
- There is indiscriminate construction activity and the subsequent ecological destruction in the Himalayan region in the name of urbanization and tourism development.
- Studies have shown that widespread settlements, farming, cattle grazing and other anthropogenic activities have destroyed the natural barriers that control avalanches and floods.
What conspiracy theorists have to say?
- Back in 1964, the Chinese tested their first nuclear weapon and India got worried because it was a next-door neighbour.
- The mishap has led to murmurs that the tragedy could possibly be linked to a nuclear device that was left behind during a joint IB (Intelligence Bureau) and CIA (Central Intelligence Agency) operation.
- Its radiations could have triggered the melting of snow as well as the glacier, argued the theorists, leading to the glacial outburst.
Last words ……
(A) The Himalayas are at the Climate edge
- The recent climate change assessment report for India shows significant melting and decline in glacier mass over the Himalayan region in recent decades due to warmer temperatures.
- There is no doubt that global warming has resulted in the warming of the region.
- Climate change-driven erratic weather patterns like increased snowfall and rainfall, warmer winters have led to the melting point of a lot of snow.
(B) Obsession with Hydropower has to be limited
- As of today, some 7,000 MW of hydroelectric projects are either operating or being constructed in this fragile region; back to back; with no respect for the river or its need to flow naturally.
- The issue is not about hydropower generation or the need for energy or development.
- It is about the carrying capacity of this fragile region, which is even more at risk because of climate change.
Way forward
We need to urgently rise up to the challenge by applying innovative and inclusive solutions that support nature and communities, to restore and rebuild a resilient future for Uttarakhand. For that, a holistic approach is required, which would work on real-time assessment of the highly vulnerable Himalayan region.
Steps that need to be taken at earliest
- Investing in resilience planning, especially in flood prevention and rapid response.
- Climate proofing the infrastructure such as by applying road stabilization technologies for fragile road networks and strengthening existing structures like bridges, culverts and tunnels.
- Strengthening embankments with adequate scientific know-how
- Reassessing development of hydropower and other public infrastructure.
- Investing in robust monitoring and early warning system.
- Establishing implementable policies and regulatory guidelines to restrict detrimental human activities, including responsible eco- and religious tourism policies.
- Investing in training and capacity building to educate and empower local communities to prevent and manage risks effectively.
Broader planning and management must include:
(a) Coherent research
- There are a lot more glaciologists and others who are working in the area and generating data.
- Multiple scientific groups and institutions are involved. But there is no coherent output. Lots of data are being generated but not being put to good use.
- There has to be one agency dedicated to the job.
(b) Monitoring
- The first step in tackling the threat from these glacial lakes is to start monitoring them and the glaciers more actively and regularly.
- There is a need to monitor every glacier. Glaciers in one basin do not have remarkably different properties.
- Relying only on satellites and remote sensing is not going to be enough.
- What is required is a consolidated state of glaciers in India, with the ability to zoom in on any of them and track the changes happening year by year.
(c) Planning
- Construction-related activities in the state might not have a direct link to Chamoli incident, but these are not entirely benign.
- The Himalayas are very young mountain systems, and extremely fragile and a minor change in orientation of the rocks can be enough to trigger landslides.
- It is important to include glaciers in any environment impact assessment for major projects such as the construction of dams.
- The entire catchment areas should be made part of the impact assessment.
(d) Mitigation
- If we monitor the glaciers regularly, it would enable us to identify the lakes that need mitigation solutions.
- Several structural and geotechnical measures can be applied, and there are successful examples where the threat from these lakes has been reduced.
- It is possible to construct channels for the gradual and regulated discharge of water from these lakes, which will reduce the pressure on them, and minimise the chances of a breach.
- At the same time, it also reduces the volume of water that goes into the flash flood. Also, alarm systems can be set up at the lakes that will warn the community downstream whenever an overflow happens.
Conclusion
- It is not possible to completely prevent these kinds of incidents. But their potential to cause destruction can certainly be minimized.
- Scientists can find a way to let the lake waters slowly drain at the nearby river at a regulated rate so that there is no flooding, and the pressure on the lake does not become unbearable.
- Such solutions can be applied in Uttarakhand, and some work is being done.
It is said that those who fail to learn from history are doomed to suffer from it repeatedly. It is high time, therefore, for the government to realize that the Himalayan Mountains are fragile and impatient.
