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  • Nepal scientists warn of glacier flood threat

Climate scientists in Nepal have warned that poor coordination of research and an inactive early warning system are putting Nepal's people at risk of flooding caused by melting glaciers.

Glacial lakes created by melting glaciers can overflow, releasing several thousand cubic metres of water per second along stream channels.

These flooding events are called glacier lake outburst floods.

There have been more than 15 of these floods in Nepal, occurring at a frequency of one every two to five years, according to the Nepalese Department of Hydrology and Meteorology (DHM).

This has been attributed to global warming, which, according to DHM research, is increasing temperatures in the Nepalese Himalayas by 0.04 degrees Celsius per year.

There are 3,252 glaciers and 2,323 lakes at or above 3,500 metres above sea level in Nepal. Twenty glacier lakes are at risk of bursting due to melting glaciers, according to a 2002 report by the International Centre for Integrated Mountain Development (ICIMOD) and the UN Environment Programme.

The situation was discussed at a conference organised by the DHM last month (23 March).

Remote sensing and satellite imaging have been used to identify potentially dangerous lakes, but field studies are limited, according to Pradeep Mool, a remote sensing specialist at ICIMOD.

He added that a lack of coordination and information sharing between researchers and institutions is leading to inadequate documentation and archiving.

Tsho Rolpa is one of the biggest and potentially dangerous glacier lakes in Nepal. Scientists predict that an outburst flood would endanger thousands of lives and cost millions of dollars in economic losses.

The DHM has already established an early warning system consisting of a network of sensors and sirens in 19 villages downstream of Tsho Rolpa.

But according to Om Ratna Bajrachary, senior divisional hydrologist at the DHM, the monitoring system has yet to be put into use because Nepal is concentrating on the establishment of peace after years of internal conflict. "We are planning to revive it," he added.

Glacial lake outburst floods first attracted scientific and government attention when the Dig Tsho glacier in Nepal's Khumbu region flooded in 1985.

The disaster completely destroyed a hydropower plant and washed away agricultural land, bridges and houses over a distance of 42 kilometres.