With recent global climate change, glaciers worldwide are retreating resulting in formation of many supra- and pro-glacial lakes. When such smaller glacial lakes start to grow bigger in area, they join to form bigger lakes and become dangerous. This and others were parts of messages conveyed during the “Technical Media Briefing on Status of Glacier and Glacier Lake in Bhutan.” It was informed that the glacial lakes do not pose immediate threat but that it needs regular monitoring,
During the Brief, director of the National Center for Hydrology (NCHM), Karma Dupchu, said that glaciers in Bhutan are very important as it is the main source of water, which he says is considered the main backbone of the country’s economy.
However, he stated that “despite the fact that these are some of our resources, they have become hazards. Since all of our settlements are along the river, it is very important that we monitor and set up early warning system.”
Talking about challenges, he said the most difficult is less data available for glacier lakes, needed to understand the impact of glacier lakes. “Within a short period of data recorded, we need a minimum of 30 years of recorded data to understand the impact of climate change,” he says, adding that the data recording for glacier lakes in Bhutan is limited to understanding the impact of glacier lakes in the country.
Another challenge faced is getting to the glacier lake site. The director said that it is extremely difficult to access the lake site. “It takes almost a month to reach the glacial lake site,” he said, “because of the high altitude, remoteness of the location, and rugged terrain along the way.”
Moreover, “Lack of capacity is another challenge faced by the glaciologist,” he said.
He also shared that a scientific organizer, the lack of scientific instrument as well as inn house instrumentation is another challenge faced by them. Unlike other developed countries, “in our country there is lack of many scientific instrument and one significant impact is seen in the field of scientific challenges,” he said.
Despite these challenges, the director said, “It is important to monitor our glacier, and our center has begun monitoring the glacier lake site; although there are many glacier lakes, we have set up two benchmark glaciers, namely Ganjuala in the headwater of Pho Chhu and Thana in the headwater of Chamkhar Chhu.”
He also added that recently they had also identified a new glacier lake in the headwater of Wangchhu.
Meanwhile, there are a total of 567 glacier lakes in Bhutan, as recorded by the Bhutan Glacier Inventory (2021), covering an area of 55.04 km2. The highest number of glacial lakes is under Punatshang Chhu (Pho Chhu). Out of the 576 total glacier lakes, 17 are categorized as potentially dangerous glacial lakes.
Similarly, Phuntsho Tshering, a glaciologist at NCHM, said, “Having experienced many GLOF, including the Lugge Lake incident in 1994, the first thing that comes to mind is disaster,” adding that after the discovery of PGDL, the mitigation is implemented, followed by the installation of an early warning system.”
They also do the regular time series monitoring for glacier lakes especially for potentially Dangerous glacial lake.
Glaciologists also stated that they regularly update the lists of PGDL and assess other glacial lakes. He stated that after re-evaluating those 25 PGDL, they arrived at 17 new PDGL.
He also shared that Time series Monitoring of PGDL is done on regular basis based on the priority. Further, Phuntsho also said that the updating of PGDL list and other glacial lakes takes place every five years.
“The assessment of other glacial lakes is taken place based on the finding from satellite,” he added. He also said, “the glacial lakes do not pose immediate threat but regular monitoring is recommended.”
Nidup Lhamo from Thimphu