The Himalayan states, Uttarakhand, Himachal Pradesh and Jammu and Kashmir, are surrounded by about 200 potentially dangerous glacial lakes formed by glacial melt, but till date no early warning system is in place to evacuate people in case these lakes breach their thin walls of debris and loose soil, a phenomenon known as glacial lake outburst flood (GLOF). A recently released report gives more reason to worry.
“Formation of Glacial Lakes in the Hindu Kush-Himalayas and GLOF Risk Assessment” by Nepal-based International Centre for Integrated Mountain Development (ICIMOD) shows that Hindu Kush-Himalayan region does not have any early flash flood warning system in place despite being surrounded by over 8,000 glacial lakes, around 200 of them potentially dangerous. North Indian states that fall in this region include Uttarakhand, Himachal Pradesh and Jammu and Kashmir, all affected by the recent extreme rainfall event.
The Hindu Kush-Himalayan land mass has much significance. Its interaction with the Indian monsoon system, together with seasonal melt of snow and glacial ice, affects the vital water supply to many of the world’s greatest rivers. Beyond the mountains, lower reaches of these river basins provide water for almost a third of humanity. Approximately 968 glaciers drain into the Ganga basin in Uttarakhand and over 4,660 glaciers feed the Indus, Shyok, Jhelum and Chenab river systems. The Ravi, Beas, Chenab and Sutlej river systems are fed by 1,375 glaciers and 611 glaciers drain into the Teesta and Brahmaputra basins and contribute between 50 – 70 per cent of the annual discharge.
A V Kulkarni, expert on Himalayan glaciers and visiting scientist at Indian Institute of Science in Bengaluru, says investigations in Indian Himalaya suggest most of the glaciers are retreating and also losing mass. This consistent shrinkage in mass and extent can affect stream runoff over a long term. In addition, this process can be further influenced if more glacial lakes are formed due to increase in debris cover and if black carbon (soot) is transported in accumulation areas of the glaciers. Therefore, continuous monitoring is needed to understand changing dynamics of Himalayan glaciers. “However, there is lack of ground base investigation of such potentially dangerous lakes,” says Kulkarni, adding that even though an exhaustive inventory of glacial lakes exists with ICIMOD, updated information is hard to come by. Kulkarni also blames lack of funds for glacial research and monitoring.
While glaciological studies have been carried out in the Hindu Kush-Himalayan region by many institutions and individuals (principally academic) over more than a century, the research has been intermittent with no systematic or coordinated long-term basis, writes Andreas Schild, director general of ICIMOD, in the foreword of the report. The National Disaster Management guidelines on floods, published in 2008, had set deadline for establishing flash floods forecasting and warning systems using Doppler radars by India Meteorological Department (IMD) by September 2009. Gopi Nath Raha, in-charge of the IMD office in Sikkim reveals the state meteorological centre has no such mechanism in place.
In the Indian Himalayan region the first glacial lake outburst flood was reported when the 1926 flood caused by the Shyok glacier in Jammu and Kashmir destroyed Abudan village and the surrounding land which were at a distance of 400 km from the burst site. Another report by scientists from National Remote Sensing Centre in Hyderabad showed sudden emptying of some of the moraine-dammed lakes (loose soil and debris that bound glacial lakes are called morain) of Shaune Garang glacier, Himachal Pradesh, in 1981 and 1988, based on high discharge measured downstream. The report stated that GLOF studies are limited and not well understood in the Indian Himalayan region.
V K Raina, former deputy director general, Geological Survey of India, says glaciologists do not want to go into the field and report the exact situation. For monitoring a glacial lake, one has to keep track of it by visiting there on a regular basis. “It is a practical problem. With a salary of Rs 10,000 why would one go to the rugged terrains of Himalayas? We did it for the love of the mountains. But we cannot expect everybody to do that,” says Raina.
He says often glaciologists raise false alarm based on data from geographic information system (GIS)-based studies. They do not even visit the site. He says the government has no dearth of funding but it is not used for the right purpose. “Like in the army they have Siachen allowance, government should give glacier allowance to make scientists visit and record glacial movements,” says Raina.
Remote sensing-based hazard assessment of glacial lakes in Sikkim Himalaya
Recession and reconstruction of Milam Glacier, Kumaon Himalaya
Snow and glaciers of the Himalayas
Glacial lakes and associated floods in the Hindu Kush-Himalayas