While Uttarakhand is still coping with its recent catastrophe, scientists have warned that nearly one-third of the state is at risk of glacier floods. On February 7, a portion of the Nanda Devi glacier possibly burst through its banks in Chamoli district. It triggered an avalanche and a deluge that ripped through the Alaknanda river system in the upper reaches of the ecologically fragile Himalayas.
A group of scientists mapped over 5,000 glacial lakes on the Indian side of the Himalayan range, and have claimed there are more than 500 glacier lakes in Uttarakhand at risk of an outburst, India Today has reported.
The report analysed the study and stated that one-third of the tehsils in Uttarakhand (26 out of 78) are vulnerable to massive glacial floods, otherwise known as Glacial Lake Outburst Flood (GLOF).
Professor AP Dimri is one of the lead authors of the study ‘Glacial Lake Outburst Flood danger in the Indian Himalayan Region’. He said the study showed the “future glacial flood danger will largely occur in the same valleys as currently affected, but the abundance of new lakes will manifest in a many-fold increase in potential GLOF frequency and few new areas will also be affected in future.” Professor Dimri also teaches environmental science at JNU.
Dimri and his colleagues used satellite data to probe the way glaciers had changed in the India Himalayan region. A team of scientists developed a Hazard Index to estimate the current and future glacial floods incidents, based on the data. They also evaluated the size and slope of the lake along with chances of avalanches to hit the lake, the report said.
It assessed the impact of potential glacial floods in the state, adding that possibilities of damages were higher in northern areas like Bhatwari, Joshimath and Dharchula.
Among the 11 Indian Himalayan states, Uttarakhand has the highest population density (182/km2) – making it vulnerable to glacial flood hazards.
“The damages could be seen in every sector, but hydel power projects and humans may face more risk in comparison to cropland and roads in Uttarakhand,” Dimri said.
Moraine dams make up more than two-thirds of the lakes in Uttarakhand. These dams are relatively fragile and can burst and cause fatal floods easily.