Experts cite impact of climate crisis
NEW DELHI: Massive inundation in Uttarakhand’s Rishi Ganga valley caused by a suspected glacial lake outburst flood on a clear winter’s day has unnerved scientists. GLOFS and resulting disasters during extreme rainfall events in glacial regions are commonly forecast by scientists. But this time scientists have seen it happen in winter, when such events are least expected.
The Snow and Avalanche Study Establishment (SASE) of the Defence Research and Development Organisation is still investigating the matter and has not been able to zero in on the exact reason for flooding as yet.
“We do not suspect an avalanche. There may be glacial lake formations, but we cannot say with certainty. We are investigating the region,” said Jimmy Kansal, joint director at SASE.
The flood caused large-scale devastation in the upper reaches of the ecologically fragile Himalayas, with over 20 labourers working on the Rishi Ganga power project missing. Homes along the way were also swept away as the waters rushed down the mountainsides.
It is difficult to say exactly what happened, said DP Dobhal, a former glaciologist at Dehradun-based Wadia Institute of Himalayan Geology.
“Locals have told me that water and debris were flowing at great speed for about 15 to 20 minutes this morning and then the flow reduced gradually. This indicates a lake outburst. It’s possible that water and debris accumulated in a lake in the glacial region of Rishi Ganga valley breached due to an avalanche. Its also possible that the avalanche took place earlier, like yesterday or very early in the morning today. The water filled up in the lake and breached. It may be very similar to what happened in 2013 with the Chorabari lake during the Kedarnath disaster. Only difference is that this time it’s in winter and that was during monsoons,” said Dobhal.
In the early hours of June 17, 2013 a flash flood came down upon the overflowing banks of the Chorabari lake in Uttarakhand. Carrying huge amounts of silt and rocks, it killed at least 5,700 people, and left unprecedented damage and destruction.
Prof Anil Kulkarni of Indian Institute of Science (IISC), Bangalore, suspected that the flooding may be linked to a GLOF.
“Several lakes have formed in the Rishi Ganga valley. We don’t know which one may have burst. In winter, the top layer of these lakes is frozen. During an ice avalanche or a landslide this top layer is breached and water can flow downstream...we have seen this in Nepal but not in Uttarakhand so far. This is a classic case of climate change impact on the glacier. We have highlighted that such disasters will become exceedingly common due to climate change as more and more glaciers retreat,” explained Kulkarni, a glaciologist and scientist at the Divecha Centre for Climate Change, IISC.
“...from the climate change perspective we can definitely say that the glaciers to the western side of the Himalayas are retreating while many of those in the eastern side have also recorded advancement of glaciers. So glacial lake disasters are expected,” said M Rajeevan, secretary, ministry of earth sciences.
We have highlighted such disasters will become common due to climate change as more glaciers retreat ANIL KULKARNI, IISC professor