Press release

Dam disaster prompts questions over energy in a changing climate

Published on 11 June 2021

A Himalayan landslide caused a debris flow so large it destroyed two hydropower stations and claimed dozens of lives, a study into the disaster has concluded

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A self-organised coalition of 53 scientists, including the University of Dundee’s Dr Simon Cook, came together in the days following the disaster at Uttarakhand, India, to investigate the cause, scope, and impact of the events that led to February’s tragedy.

Their study, which analysed satellite imagery, seismic records, and eyewitness videos to produce computer models of the flow, has been published today in the journal, Science.

Dr Cook says that the report findings raise questions about energy sustainability in a changing climate.

“It’s very difficult to attribute any single event, such as this, to a climate change trigger,” he said.

“What we can say is that climate change makes these events more likely because permafrost thaw and glacier melt makes these environments even more unstable.

“It is also worth remembering that this was only a ‘disaster’ because two hydropower schemes had been built in this valley. Clearly, we need to move to more sustainable energy sources, but we need also to be mindful of the risks posed to these installations by climate change and associated changes in high-mountain landscapes.

“This is something that we’re already working on in other parts of the world, such as the Peruvian Andes, where hydropower is central to energy security, but is vulnerable to similar changes in climate and landscape.”

The disaster occurred on February 7, when a veritable wall of rock and ice collapsed and formed a debris flow that barrelled down the Ronti Gad, Rishiganga, and Dhauliganga river valleys.

The massive slide was caused when a wedge of rock carrying a steep hanging glacier broke off a ridge in the Himalayan mountain range. The resulting debris flow led to the destruction of two hydropower generating facilities and left more than 70 people dead or missing.

Lead author Dr Dan Shugar, associate professor in the Department of Geoscience at the University of Calgary, used high-resolution satellite imagery provided by MAXAR, PlanetLabs, and CNES to determine the cause of the Uttarakhand disaster. While initial suggestions pointed to a glacial lake outburst flood, Shugar confirms that there are no glacial lakes of any size large enough to produce a flood anywhere near the site.

“High resolution satellite imagery used as the disaster unfolded was critical to helping us understand the event in almost real time,” he said.

“We tracked a plume of dust and water to a conspicuous dark patch high on a steep slope. This was the source of a giant landslide that triggered the cascade of events and caused immense death and destruction.”

The Science paper provided satellite evidence that previous large ice masses had been dislodged from the same ridge and struck the same valley area in recent years. The researchers suggest that climate change is contributing to such events happening more frequently, and that the greater magnitude of the latest disaster is an argument in favour of avoiding further developments in the area.

Notes to editors

The University of Dundee has been named in fifth position globally in the Climate Action category of Times Higher Education’s Impact Rankings 2021.

You can read more about Dr Cook’s work on climate change and glaciers here.

Image details: “Destroyed Tapovan Vishnugad hydroelectric plant after devastating debris flow of Feb 7, 2021. Photo: Irfan Rashid, Department of Geoinformatics, University of Kashmir”


Jessica Rorke

Media Relations Officer

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Story category COP26, Research
Collection Climate Action