What caused the “shocking” landslide that destroyed a Himalayan village?
It was a shocking scene captured on video: a torrent of water, mud and rock that slaps in the Himalayan village of Dharali with such strength that he dropped the buildings of their foundations and buried houses on their roofs in an instant.
In a video that circulated on social networks and that CBC News has checked, you can see residents of the Indian state in the northeast of Uttarakhand try to flee while the torrent collapsed on Tuesday mountains.
It is estimated that 360 million cubic meters of debris entered the village in a few seconds.
At the end of the week, dozens of people were still missing, while officials confirmed at least six dead.
It is the monsoon season in India, but the experts are studying if a phenomenon known as Cloudburst – sudden and intense precipitation in a small place – has caused a disaster or if it has been caused by a breach of ice lake.
While Indian officials face reactions on development regulations that could have aggravated the situation, scientists say that climate change caused by man exacerbates the potential of new catastrophic events like this.
It was “shocking and intestinal” to see what happened in Dharali, told CBC News, Raghu Murtugudde air conditioner at CBC News in an interview with Mumbai.
He says that India has some of the highest mountains in the world, but communities that have lived there peacefully “for decades have now been more vulnerable to disasters due to climate change.
Here is what we know about what happened in Dharali and the factors that could have led to the disaster.
See how fast the flower flow of the flashflood submerges the retaining walls put on the Kheer Ganga stream bed. The inhabitants of Dharali, Uttarkashi, Uttarakhand lived with a false feeling of security. Horrible sequences.pic.twitter.com/nexafi09sj
Where is Dharali?
Dharali is located more than 350 kilometers northeast of the Indian capital New Delhi.
It is located at an altitude of 2,600 meters along the Bhagirathi river, on the Himalayan mountain slopes in the northeast Uttarakhand.
It housed less than 1,000 people before the disaster.
It is a domestic tourist place and a stand at the stand for climbing Hindu pilgrims in the city of the Temple of Gangotri and, according to Indian Express, Dharali and other neighboring communities organized a religious festival this week.
Many houses, hotels and other buildings have been built on each side of another river which flows seven kilometers from the end of a glacier, at an altitude of 6,700 meters, to empty in the Bhagirathi.
In recent years, other places in Uttarakhand have experienced similar disasters – but even more deadly -. Up to 6,000 people died in June 2013 when extreme precipitation caused floods, landslides and a violation of the glacial lake near the mountain city of Kedarnath.
Then, in February 2021, nearly 200 people died in a neighboring district when part of a glacier broke, causing an avalanche of ice, rock and water which sparked floods along the river valleys below.
Was it a Cloudburst-and what exactly is it?
The first reports on the disaster suggested that an explosion of clouds may have taken place in the region.
It is at this moment that the hot and humid air with a lower altitude is forced on the mountain slopes where it mixes with fresh air and creates a huge storm cloud.
The humidity droplets in the cloud expand and new droplets are formed like strong ascending air currents prevent the droplets from falling.
When the cloud can no longer contain the water, it bursts, quickly releasing a massive quantity of rain – at least 100 millimeters per hour in an area of 20 to 30 square kilometers below – often causing sudden floods and landslides.
Some meteorologists say that the amount of rain that fell in Dharali and elsewhere in Uttarakhand that day was not enough to suggest a Cloudburst.
But there were no cloud monitors in this area and precipitation could have been more important at higher altitudes, said Murtugudde, who is a member of the faculty invited to the Kanpur Indian Institute of Technology and Emeritus Professor at the University of Maryland.
“So, we don’t have the data yet and we may not have it anytime soon,” he said.
Cloudburst or not, says Murtugudde, the weather calculation that brought heavy rain to the region could have been a factor in the Dharali disaster.
He says that the monsoon season of the Indian subcontinent is powered by the hot air from the Oman Sea. But climate change has contributed to the increase in temperatures in the Middle East and to the Mediterranean region which “draw” from the warmer air further north and “pumping” more humidity in the foothills of the Himalayas.
Not only does it bring more precipitation, he said, it also contributes to the melting of glaciers and the creation of glacial lakes.
A mother and a father tell when they learned the sudden flood and the landslide that struck the village of Himalayas in Dharali on Tuesday – and how they talked with one of their children before the telephone connection was lost and they no longer heard.
Has a glacial lake collapsed?
Another potential cause of the sudden flood and the landslide in Dharali which is known as a lighting flood of the glacial lake.
“Immense floods of the glacial lake which are a combination of ice, sediment, rocks which can have fairly disastrous impacts not only on infrastructure but also for loss of life,” said Rodrigo Narro Pérez, assistant professor at the Earth School, the Environment and the Society of McMaster University.
The glacial lakes, he explains, are held by natural dams, called moraines, which can be composed of ice as well as loose sediments and rocks.
He says there can be different factors that make this natural dam fails and unleashes all melting water.
In some cases, the pressure of precipitation breaks the moraine, or the strength of a large mass, such as an avalanche or a landslide, could break the whore.
In Dharali, he said, it may have even been a combination of the two.
Narro Pérez says that Himalayas are more at risk that it will happen. There are 7,500 glacial lakes in the Indian Himalayas, and their overall volume has increased – 50% in 30 years, according to a study of 2020.
But he says that there are only surveillance systems for 190 which are considered a high risk, leaving few possibilities of early alert and the potential to save lives.
He underlines another disaster in Switzerland, in May, where a rocky slide from a glacier buried 90% of the village of Blatten.
The difference, he says, is that there was an early alert system in place and that the officials had evacuated the village a few days earlier. Only one life has been lost.
“But it’s a game of figures,” he said. “Over the past two years, we have seen the number of glacier lakes exponentially increasing – not only in terms of number, but also in volume.”
A huge piece of glacier in the Swiss Alps broke, sending a wave of ice, mud and rocks crash on Blatten. The managers say that the mountain village was evacuated at the time, but a person was missing.
What is the factor in climate change?
There are many variables that have led to what happened in Dharali, explains Prasoon Singh, a scholarship holder from the Earth Science and Climate Change Division of The Energy Resources Institute based in New Delhi.
He told Reuters that the impacts caused by humans, such as deforestation and land management, may also have been a factor in this disaster.
Others criticized the local government for lax construction regulations and allowed development along the bed of the river.
But whatever, says Singh, such disasters increase in frequency and intensity, and “which can be attributed directly to the evolution of climatic conditions”.
And even if there had been warning systems and effective measures in place, the “risk is never zero” and it is only getting worse with climate change, explains Murtugudde.
Adaptation can be a local concern, he says, but the attenuation of global warming requires international cooperation.
“Rich and poor has no importance … global warming does not create any winner,” he said.
Strong rains have caused sudden floods and mudslides in northern India, washing the houses and leaving more than 100 disappeared.
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