| Bhutan's
glaciers and glacial lakes: Lunana |
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Bhutan Glaciers - Glacial Lakes |
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Bhutan Information |
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Lunana's
glaciers are melting
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| Eight
years ago a glacial lake in Lunana region burst, wreaking havoc
down the Punakha- Wangdue Phodrang valley. After several forays in
the area by experts there is still no hope of a permanent solution and
the government is making attempts to reduce risks. |
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According to a report
published by the International Centre for Integrated Mountain Development
ICIMOD and UNEP, 24 out of 2,674
glacial lakes in Bhutan are "potentially dangerous",
meaning that they could burst.
Of
these eight lakes are in the basin that feeds the Pho Chhu which
flooded in 1994,
five in the Mo Chhu basin, seven in the Mangde Chhu basin,
three in the Chamkhar Chhu basin and one in the Kuri Chu basin.
They are all fed by glaciers which are reported to be melting because of
"accelerating global warming".
Covering
an area of 1,317 square kilometers most of the 677 known glaciers in
Bhutan have spawned "many dangerous moraine-damned lakes" which are
"increasing in size at a very fast rate". These natural dams may, because
of huge amount of accumulated water, suddenly break like the Luggye
Tsho that caused the Punakha flood, discharging large volumes
of water and debris. Some glaciers are retreating by about 20 meters
to 30 meters every year.
While
most of the lakes that lie in the Lunana region do not pose an immediate
threat, two glacial lakes, Raphstreng Tsho and Thorthormi (Thortomi)
Tsho, both at the source of the Pho Chhu, are considered risky,
with the latter predicted to burst in 15 to 20 years.The findings were
made by numerous expeditions in the Lunana area after the 1994 flood.
The
flood from the Luggye Tsho had apparently damaged the dams of the Raphstreng
Tsho and mitigation work on it was undertaken by an Indo-Bhutan team to
reduce the "hydrostatic pressure" on the weakened dam in 1996.
The
depth of the lake was also partially lowered. However, this particular
lake seems to have drawn considerable attention from experts since the 1980s
and long after the Luggye Tsho burst in 1994.
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Glacial
lake in Lunana
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Although
there is no immediate danger, the presence of a peculiar micro - organism
on the surfaces of glaciers could accelerate glacial melting and eventually
lead to a glacial outburst, according to a preliminary survey report conducted
by a Japan - Bhutan survey team which included a glacier - microbiologist,
glacio - ecologist and geologist.
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| Luggye
Lake |
Luggye
Glacier |
Raphstreng
Tsho |
| Why we need climate action to avert glacial lake outburst floods in Bhutan |
The mountainous Kingdom of Bhutan was the first carbon-negative country in the world but lives under the constant threat of climate change.
Its glaciers are melting fast as temperatures rise, raising water levels in the glacial lakes and magnifying the risk of an outburst flood.
The world 's major carbon emitters must consider accelerated actions and take responsibility for turning the tide on climate change.
At 4,200 metres above sea level, the remote highland community of Lunana - made up of a cluster of 17 villages - is a place almost untouched by visitors.
Tucked away in a corner of the tiny Kingdom of Bhutan, it takes seven days to trek here from the capital Thimphu. The only other way in, depending on the weather, is a helicopter ride that follows the river bending and weaving between the mountains.
Lunana inherits its allure from its geography. A place ringed by majestic snow-capped mountains, stunning glaciers, and turquoise glacial lakes, a beauty that is captivating but today is potentially lethal.
Glaciologist Karma calls that danger "a tsunami in the sky", a threat that is brewing in these mountains that could lead to another glacial lake outburst flood, also known as GLOF.
Lunana is home to four glacial lakes - Luggye, Thorthomi, Rahpstreng and Beytsho. The first three are among Bhutan 's 17 most dangerous glacial lakes. As temperatures get warmer, the glaciers are fast melting, raising water levels in the glacial lakes, and magnifying the risk of an outburst flood.
Bhutan bears the climate consequences of other countries' emissions
Bhutan does not contribute to global warming. In fact, it is the first carbon-negative country in the world, yet it must now bear the consequences of the actions of other countries, both near and far from its borders.
Karma and his team, from the National Center for Hydrology and Meteorology - who spend several months in Lunana every year monitoring the glaciers and lakes - have long warned about a worst-case scenario of a combined explosion of water from the Thorthomi and Raphstreng glacial lakes.
The two lakes are separated by a thin, weak ridge, whose collapse would lead to the convergence of the two lakes, triggering a massive outburst flood, four times more severe than the one in 1994.
This would devastate not only communities in Lunana, but also several others downstream, and it would destroy two of Bhutan 's biggest hydropower projects, the 1200-megawatt Punatsangchhu I and 1020-megawatt Punatsangchhu II. Hydropower is the country 's largest export, irrigates its agricultural base and hence contributes heavily to its economy.
In Lunana, the outburst of 1994 remains a vivid memory. When I visited the area last month, Wangmo, a woman from the village of Tenchoe told me about how she and others in the community ran for their lives when the flood struck.
It was around 9pm, when they heard a fearsome rumbling, and guessed a flood was coming. It was dark as they rushed out of their homes, carrying children and the elderly to higher ground, Wangmo said. Despite their quick response the flood claimed nearly two dozen lives and destroyed homes, farms, infrastructure, and biodiversity, in Lunana as well as downstream communities. It took a long while to build back and they are older now.
So today, even the slightest of sound from the mountains is cause for concern. Villagers are witnessing the changes around them almost in real time. The Thorthormi glacier is retreating at about 30 to 35 metres per year. In case of a lake outburst, the people of Thanza, the closest community to the lakes, have only 20 minutes to move to safer ground.
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| Source: WEF, 1 November 2022 |
| Author: Kanni Wignaraja, UN Assistant Secretary-General and UNDP Regional Director for Asia and the Pacific, United Nations Development Programme (UNDP) |
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