Uttarakhand flood ‘quite peculiar’: Scientists to study cause - what we know so far

"The teams will study the reasons behind the incident. Our teams will be looking into different aspects of glaciology," Sain said.

As per the report, the scientists have studied glaciers and seismic activities in the Himalayas and were also part of the study of the 2013 Uttarakhand flash floods.

Likely cause of flood:

Kalachand Sain stated a ‘glacial burst’ is widely considered the cause (also the cause of the 2013 Uttarakhand floods), with a close second reason being a possible cloudburst. Sain however added the incident was ‘quite peculiar’ due to no reported snow or rain on the day of the incident.

In case of a glacial burst or Glacial Lake Outburst Flood (GLOF), usual paths of the glacier may burst due to increasing pressure or external reasons which can cause widespread flooding.

Assistant Professor Mohammad Farooq Azam with IIT-Indore called this a “rare possibility” as Google Earth images do not show a glacial lake near the area of incident. “We need further analysis, weather reports and data to confirm if this indeed was the case," he said.

In the event of a cloudburst, Professor AP Dimri from the School of Environmental Sciences at Jawaharlal Nehru University said the possibility while “rare” could be considered “during this time of the year” adding: “It does look like a GLOF event right now.”

Another explanation is climate change, with Prof Azam citing increasing “thermal profile of ice” which has gone from -6 to -20C to -2C, thus making it more susceptible to melt.

Anjal Prakash of the Intergovernmental Panel on Climate Change (IPCC) also backed the climate theory, calling the global warming situation “irreversible now.”

Also Read | Did the rising number of dams in Uttarakhand trigger the disaster?

There is also criticism of the hydel projects, with environmental experts blaming increasing human intervention in the ecologicall- sensitive Himalayan region for making it more vulnerable to climate change.

“Heavy construction work in the fragile eco-sensitive zones should be avoided,” Avinash Chanchal, senior climate and energy campaigner, Greenpeace India said.

What we know so far:

Uttarakhand’s Chamoli district experienced avalanche and massive flooding on February 7 after a portion of the Nanda Devi glacier broke off causing overflow of the Alaknanda river system — consisting of the Alaknanda river, the Dhauli Ganga and the Rishi Ganga — all tributaries of the Ganga.

The sudden floods washed away hydroelectric stations — the Rishi Ganga Hydel Project (Raini) and NTPC’s Tapovan-Vishnugad Hydel project (Tapovan) — on the river system and killed at least 10 people so far. Another 143 are missing as scores of labourers were trapped in tunnels due to the sudden water rush.

“There were 153 people missing from the two hydel projects at Raini and Tapovan out of which 10 bodies have been recovered while 143 are still missing. The efforts are focussed at the moment on rescuing 30-35 people trapped in a 250-metre-long tunnel at Tapovan,” Uttarakhand DGP Ashok Kumar told PTI.

Progress in rescue efforts:

Teams of the Indian Air Force (IAF) have also left for the avalanche-hit areas to ramp up relief efforts.

“Though all arrangements are in place there is no need for any helicopter rescue in the affected areas. Only two villages including Raini are cut off where essentials are being supplied,” the DGP said.

Besides the hydel projects, civilian houses in the path of the flood waters down mountain sides were also swept away. There is fear of damage in human settlements downstream, including in heavily populated areas. Many villages were evacuated and people taken to safer areas.

(With inputs from PTI)