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In June, a glacial lake burst through its banks, killing thousands. Expect more such ‘mega-floods,’ experts say.
NEW DELHI, India — This summer’s devastating “Himalayan tsunami” is a grim omen for the future of the millions of people living downstream from the majestic mountain range.
The June floods wiped out the Hindu pilgrimage town of Kedarnath and may have killed as many as 6,000 people.
But the scale of the disaster could be dwarfed by future flooding, experts warn.
“The Kedarnath floods may be only a small precursor to never-seen-before mega floods,” Maharaj K. Pandit, director of Delhi University's Center for Inter-disciplinary Studies of Mountain & Hill Environments, told India Today.
According to preliminary studies, dozens of houses were smashed and hundreds of religious pilgrims were swept away when a lake above the eighth century Kedarnath Temple burst its natural dam of loosely packed glacial sediment, sending a sudden deluge of water down on the town.
Many now believe it was an accident waiting to happen — and similar accidents will happen again and again as the region gets warmer.
Rising temperatures due to global warming are fast creating thousands of glacial lakes across the region. The growing volume of meltwater is dangerously increasing the risk of sudden glacial lake outburst floods (GLOF), according to the Kathmandu-based International Center for Integrated Mountain Development (ICIMOD).
As the volume of water increases, so does the pressure on the dams of ice or glacial sediment, called moraine, which hold the lake in place on the side of the mountain. Once that pressure reaches the tipping point, heavy rainfall from a sudden cloudburst, a landslide, or an earthquake can breach the dam, sending a deadly torrent of ice, rock and water down on the people living below.
The results can be catastrophic.
In the weeks following the June 17 flood disaster, tens of thousands of residents, tourists and religious pilgrims were successfully evacuated. But officials still believe there are at least 5,748 people missing across the north Indian state of Uttarakhand.
Their survival is unlikely, even if Uttarakhand Chief Minister Vijay Bahuguna has so far refused to declare them dead.
Meanwhile, it will cost hundreds of millions of dollars to rebuild homes, lay new roads, replace destroyed bridges and restore power lines, Bahuguna estimates.
"Around 200 of my bridges have been washed away, nearly 5,000 roads damaged, connectivity to 4,300 villages snapped — electricity and water supplies disrupted, telephone lines collapsed," the chief minister told Reuters.
In some ways the epicenter of the tragedy, Kedarnath, looms largest in the minds of many experts. Around the region, countless other areas face similar threats.
“When you talk about glacial lakes, in Nepal alone there are more than 1,400 lakes, and if you talk about the whole Himalayan Range ... there are about 20,000 glacial lakes,” Pradeep Mool, who monitors the risk of glacial lake outbursts for ICIMOD.
More than 200 of these lakes have been classified as potentially dangerous. Some of them — like a 250-acre lake holding 5 billion gallons of meltwater high in the mountains of the northeast Indian state of Sikkim — could affect people living hundreds of miles downstream.
Precious few of these lakes even existed a few decades ago.
“When I look at some of the lakes, especially in the Nepal Himalayas, where I have done detailed field work, [it's shocking how fast they have grown],” Mool said.
“In the case of Imja lake, for instance, there was no lake there at all 50 years back. When I ask the people, they say ‘It was a tiny pond when I was a kid.’ Now it's already about 580 meters wide and 2.3 kilometers long and about 100 meters deep.”
That's particularly ominous as torrential monsoon rains sweep across Uttarakhand again last week, hampering the rebuilding effort with new deadly landslides.
Along with the new meltwater, increasingly frequent cloudbursts endanger the villages and cities of both Uttarakhand and Himachal Pradesh — where there are some 250 glacial lakes above population centers like the tourist town of Manali.
Already, images from remote sensing satellites show that the water level in Parchu Lake, in Tibet, is rising rapidly, putting some two dozen towns and villages along India's Sutlej River in Himachal Pradesh at risk, according to another India Today report.
A 2005 outburst from the lake that caused some $300 million in damage has prompted local authorities to draw up plans for the evacuation of these areas, officials say. But in the watershed areas of countless other Himalayan lakes, India remains woefully unprepared.
“Unfortunately, we still have no mechanism to incorporate good science into policy,” Delhi University's Pandit told GlobalPost. “There is not even any talk about these serious scientific issues.”