Flash floods may triple in the “Third Pole” with the ongoing climate change posing a danger, according to researchers from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences and the University of Geneva.
“Third Pole” of the Earth comprises of the Hindu Kush-Himalaya, Tibetan Plateau and surrounding mountain ranges. The region has the largest number of glaciers outside the Polar Regions.
Nature Climate Change published the findings. The findings gain significance in the wake of recent avalanches and flash floods in the Himalayan region.
GLACIAL LAKES
The researchers noted that global warming and melting of glaciers over the Third Pole caused rapid expansion and formation of glacial lakes. They said that when water is suddenly released from these lakes through dam failure or overtopping, glacial lake outburst floods occur. These pose a severe threat to downstream communities.
HIGH THREAT
The scientists used mainly focused on threat from new lake formations in front of rapidly retreating glaciers. They looked at satellite imagery and topographic modelling to see the risk associated with about 7,000 glacial lakes in the Third Pole. They pointed out that one in six (as many as 1,203) of the present glacial lakes pose a high to very high risk to downstream communities.
The researchers claimed that much of the ‘Third Pole’ might approach peak risk for glacial lake flooding by the end of the 21st century or even by the middle of the century. They also noted the possibility of expansion of more than 13,000 lakes in the coming years and the lakes growing closer to steep mountain slopes. These may crash into lakes and provoke small tsunamis, they added.
The scientists warned that the number of lakes that comes under the high or very high-risk category would increase from 1,203 to 2,963 if global warming continues on its current path. This will lead to new risk hotspots emerging in the western Himalaya, Karakorum and parts of Central Asia, they said. All these regions have witnessed glacial lake outburst floods earlier.
