Sikkim: Deadly Indian glacial lake flash flood exposes lack of warning system

According to experts, India immediately needs to fit sophisticated early warning systems for its hazardous glacial rivers after a deadly flash flood in the north-eastern state of Sikkim.

After South Lhonak, a glacial lake in the Himalayas, burst its banks last week, at least 70 people — including nine soldiers — have died and more than 100 others are still missing.

For outbursts, as well as the abrupt discharge of water from a glacier-fed river, can be brought on by torrential rain, seismic events, or mudslides.

Authorities can leave people quickly and available the flood gates from upstream dams with the aid of an early warning system to reduce damage.

India’s National Disaster Management Authority( NDMA ) revealed that it had surveyed two at-risk lakes in early September in order to set up early warning systems for real-time alerts in the event of glacial lake outbursts following the Sikkim disaster.

According to the BBC, one of the lake surveyed was at South Lhonak, where some job for first instructions was started.

But given that the river has long been known to be dangerous, the flood that occurred just a few weeks afterwards has caused people to wonder why there wasn’t an effective early warning system in place now.

It is still unclear what sparked the South Lhonak explosion. While some claim a cloudburst may have caused it, others claim there was no such large, concentrated downpour.

They blame the moraines, which are made up of soft boulders, rocks, and soil at the glacial lake’s edge, for the catastrophe. Some have even connected it to a seismic event.

There was a great chance of South Lhonak river flooding, according to several reports.

A fast melting ice that feeds the lake had caused its region to grow more than 2.5 times over the previous three decades. To stop the lake from overflowing in 2016, government withdrew some of its waters. However, there was no early warning system in place.

When instructed to open the groundwater floodgates, workers at the Chungthang bridge, which is upstream of the Teesta valley and collapsed due to the flood, claimed it was too late because flood waters had already begun to hit the facilities.

According to experts, glaciers are melting more quickly as a result of global warming, which has raised the water levels in some Alpine lakes.

Additionally, it has resulted in the formation of new rivers or the fusion of ancient lake. These lakes are now hazardous because avalanches, cloudbursts, and rockfalls may cause them to disaster.

The NDMA states that it intends to” fit early warning systems for real-time emails at most of 56 at-risk glacial rivers in India.”

Up to 200 glacial rivers across the Himalayas are thought to be in a hazardous condition, according to the International Centre for Integrated Mountain Development, an NGO that specializes in Healayan risks. They may, in other words, suddenly tumble, just like South Lhonak.

More than 700 small and large glacial rivers can be found in Sikkim only, and researchers estimate that about 20 of them are at risk of bursting.

Lhonak was being watched and classified as unsafe, according to Dhiren Shrestha, chairman of Sikkim’s science and technology division. However, he chose not to respond to the BBC’s inquiries regarding the lack of an early warning system and the subsequent notification of towns and significant houses inland.

The NDMA, the Central Water Commission, and the Ministry of Water Resources were among the other governmental organizations in India that did not respond to these queries.

In South Lhonak, Switzerland has assisted the NDMA in installing an early-warning method. The BBC was never given any information or an explanation for why the job was taking so long by its ambassador in Delhi.

Rejeev Rajak, a glaciology scholar at Sikkim University, said that” Apparently the lack of an early warning system has to do with government and also the fact that some national and international firms are involved in this job ] setting up the system.”

According to some politicians who have been opposing the building of reservoirs on rivers that originate in the Himalayas, South Lhonak Lake was delicate from a defensive standpoint, which may have slowed down the implementation of the warning system.

A candidate who declined to be named said,” The river is in the area that borders China’s autonomous area of Tibet, and that definitely entails military differences which means any non-military work will take day.”

However, glaciologists claim that changes brought on by global warming are occurring quickly in the Himalayas and call for ongoing surveillance and risk-reduction measures.

Senior cryosphere specialist Miriam Jackson of the International Centre for Integrated Mountain Development( ICIMOD ) said,” We are running out of time.”

She continued,” And there is a ton of work to be done, such as keeping an eye on the lake, setting up early warning systems, involving the local populations, and ensuring that the tracking and alerting equipment is kept up.”

However, as the climate has warmed, there are more and more things that make glacial lakes dangerous.

Historically, the key issue was typically thought to be fast-melting glaciers fast filling up glacial lakes. However, the thinning and retreating glaciers have also made the landscape of the area more fragile, causing rockfalls and mudslides.

According to experts, rising temperatures are causing geographical instability in mountainous areas around the world, including the Himalayas, which will result in storms at higher altitudes where it has typically snowed in the past.

Heat also entails the melting of permafrost( area that would otherwise remain completely frozen on mountains ), which can result in slope failures( a slope that collapses suddenly as a result of rain or other factors) and flood glacial lakes.

According to Jacob Steiner, an ICIMOD researcher,” there is proof that the hill that caused the South Lhonak to storm moved faster than it has in decades.”

” Scientists are currently examining side failures across all lakes using satellite images, mapping every side around every lake, and determining how many have moved exceptionally quickly.”

However, if early warning systems are in place for when a glacier lake bursts, as South Lhonak did next year, none of that surveillance will be useful.

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