The importance of glaciers, especially the threat posed by melting glaciers, was fully realized only after the incident of the Glacial Lake Outburst Floods (GLOF) in 1994.
The sporadic studies done on glaciers in Bhutan before 1994 did not have much focus. Therefore, realizing the importance of glaciers, in 2000 to 2001, Department of Geology and Mines (DGM) in collaboration with ICIMOD, Nepal came out with the first inventory of glaciers and glacier lakes in Bhutan mentioning the existence of 667 glaciers and more than 2,700 glacier lakes.
Of the glacier lakes, they have identified and categorized 24 glaciers lakes as potentially dangerous to cause GLOF in future.
Respectively, the second inventory was published in 2019 wherein the number of glaciers in the country has increased to 700, showing an increase of 33 glaciers from 2001.
In the context of climate change, people have the mindset that the number of glaciers should be decreasing or disappearing with the melting of glacier, however, they found out that the number of glaciers has increased because of the disintegration of glaciers.
Tshering is a 72-year-old man from Pazhi, and he said that it is distressing to see glaciers melting at a very high speed, mountains covered with snow is disappearing with time, and this leaves highlanders in much fear of losing their settlements to disasters.
He said, “Younger generation will have the option to leaving the land and kick starting a new beginning, while we the older generation will be left with no choice than to sacrifice everything to the disaster. Climate change is taking place, and the existence of highlanders will be lost in another few decades.”
Laya is surrounded by lakes. If not two, one of the lakes will burst in future, he said, adding that this will destroy the settlement downstream taking lives of people and yaks.
53-year-old Zam from Toedkor said, “In one decade, we have seen various changes in terms of weather. Lakes started growing due to glacier melting. We live in fear of lake outburst anytime. The incident of landslide in recent times taking many lives put us in more fear.”
The highlanders said they want to run from the dangerous place and start a settlement far from the threat of GLOF, however, there is no place they can go. So, they continue to survive even with the fear of the impending GLOF.
She said, “GLOF will not only destroy the human settlement but will also have impact on the wildlife and yaks in particular. We hope that the government will plan to protect the highlanders from the GLOF.”
61-year-old Lhakpa Tshering from Lungo said, “Climate change is happening as we can see change in the weather pattern. We started experiencing heat unexpectedly. We are surrounded by glacier lakes, some posing risk to our settlement if the lake bursts.”
Likewise, many highlanders have shared their concerns and fear over the chances of their settlements being wiped off by GLOF. They know it is natural, however, they are urging the government to look for a ways to tackle or avert the disaster from happening.
A specialist from the National Center for Hydrology and Metrology (NCHM), Karma, said that since the publication of the first glacier inventory in 2001, they tried to do ground checks by doing field visits.
He said, “Though, the record of potentially dangerous lakes is 25, after thorough study and field visit, the number has come down to 17 qualifying as potentially dangerous. We also have identified three benchmark glaciers (clean ice glaciers), Thara glacier at Chamkharchu, Zhodho glacier at Thimphu and Gangjula glacier at Pho-Chu.”
The benchmark is to see and monitor the status of the glaciers. The experts are basically monitoring the mass balance through which they will be able to determine how healthy is the glacier. They will also monitor the terminals to see if the glacier is decreasing or advancing annually.
Not all the glaciers are behaving in same manner. He said that the glaciers in Lunana are debris covered glaciers, hugely associated with huge moraine dam glacier lakes. This type of glaciers melts 30 to 35 mts annually. The melting rate of clean ice glaciers is 11 to 16 mts annually on average.
The glaciers in Lunana, being huge, whatever melts get accumulated forming various glaciers lakes. Due to high speed of glaciers melting, the water level increases which ultimately has the risk hazards.
He said, “A time will come in future where the hydro static pressure build-up by the melt water accumulating inside the moraine dam exceeds and burst, which is GLOF. In the process, this may have greater impact on the highlanders and their settlements. The settlement in Lunana is more vulnerable to the hazard.”
Meanwhile, he said that in-order to reduce the impact and risk of GLOF on the vulnerable communities in the downstream region, they are following three methods. They are studying the lakes, how critical they are and the impact it will have if in case it outburst.
He further said, “From those studies, we will be able to do hazard tradition map. We have done in Punatshanchu, Mangdechu and Chamkharchu. Maps are colour coded risk wise, just in case the lakes in Lunana outburst.”
The other methods are to reduce and bring down the water level in the most critical lakes. In the Throthormi lakes, in four years (2009 to 2012) they have artificially drained out 17 million cubic meters of water. This kind of intervention has reduced the hazard of GLOF from Thorthormi lake by the magnitude of 1994 GLOF.
That way, he said, “If even if GLOF happens, the flood volume is reduced. For the mitigation work, we have spent around USD 4 million.”
To bring down the risk of GLOF to zero, water from the lakes have to be drained out completely, which is not at all possible, moreover it is actually not good environmentally.
Therefore, the experts have resorted to installation of early warning system as a third method. Reducing the risk of hazard in future is installing the system, given that it is fully strengthen.
“We have installed a system in Punatshangchu, whereby everything is connected to a censor in the lakes in Lunana. Should something go wrong, we can than pick up the signal. This is monitored 24/7. We have same system installed in Wangdue, Chamkhar and Mangdechu,” he added.
Early warning systems are installed in major river basins, and those systems are flood detection systems, whereby they relay the information if flood takes place. However, he said that they should not just be confined to just the detection.
To provide more lead to the people in the downstream, they are working on the flood forecasting. Enhancing the system will give them the opportunity to warn people so that they have enough time to evacuate, he said.
Lunana Gup Kaka have shared his concerns over the risk of lake outburst anytime due to high speed of glacier melting every year. If this happens, the outburst will not only impact few Chiwogs of Lunana but also settlements in Punakha and Wangdue.
He said, “Knowing the risk, our government with a fund support from international agencies have given us a budgetary support to drain out the water from the lake to reduce the water level. However, carrying out such initiative manually may not be that effective in the long run. It would be of greater help if machines can be deployed.”
Glaciers are melting at a faster rate due to climate change, he said, adding that they are witnessing lesser snow coverage in the mountains each year. In addition, “The Thorthormi lakes used to be a solid ice in the past. Today, we started seeing melting of ice turning it into water lake slowly. If this happens at a faster rate, the risk of lake outburst is even higher,” he added.
He further said that there is no protection, as such, if the outburst happens, however, the people are advocated on the risks, and on how to immediately leave the place upon receiving the signal of danger.
There are more than 200 households and 900 people living in Lunana.
The story is funded by BMF’s project titled “Strengthening the capacity of Bhutanese Media for Climate Change Reporting,” supported by Canada Fund for Local Initiatives.