Hindustan Times
Living with the threat of climate change
Bishnu Gopal Shrestha, a resident of Barabise in Sidhupalchowk district of Nepal bordering the Tibet Autonomous Region of China, knows what living on the edge is like, literally. Every year during floods, he and his neighbours remain alert lest they and their house are swept away.
“Whenever there is a threat of flash floods, we flee from our homes. And when things become normal, we return,” he says. Like him, many residing in this difficult terrain have made the river basin their home and face constant threat to their lives and properties.
The fear is not unjustified. Shrestha and hundreds of others who reside close to the Bhote Koshi River in this small trading town on the Arniko Highway, the only highway linking Nepal and China, are potential victims of the threat posed by climate change and global warming.
In July 1981, floods caused by outburst of Zhangzangbo, a glacial lake in the Tibetan side of the Poiqu/Bhote Koshi basin swept away 5 persons, injured 191, swept away 41 houses and damaged 12 bridges and 27 kilometres of the highway blocking traffic for over a month.
The Poiqu River originates in Tibet and is called Bhote Koshi after it enters Nepal. Its name changes to Sun Koshi after a small tributary with the same name joins it near Barabise, located few kilometers from the Nepal-China border in Liping.
According to an analysis done by the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD), there are nine potentially dangerous glacial lakes including Zhangzangbo in the Poiqu/Bhote Koshi basin—all located in Tibet.
Rapid deglaciation or shrinking of glaciers in the basin as a result of climate change has led to an increase in number of glacial lakes. The area of these lakes is on the rise and any glacial lake outburst flood (GLOF) could cause immense damage in Barabise and other areas downstream.
Nepal has experienced at least 24 GLOFs in the past—14 occurring within the country and rest result of flood surge overspills across the China-Nepal border. The Poiqu/Bhote Koshi basin has witnessed three GLOFs including the one in 1981.
But with the growing threat of climate change and presence of significantly larger glacial lakes, it is envisaged that potential GLOFs in the region could be of larger magnitude than the 1981 event and cause much more damage.
Over the past three decades, many people have shifted from hilltops and settled along the highway and the river basin. With the rise in population and buildings, there has also been increase in number of bridges and hydropower stations in the region—exposing them all to GLOF threat.
“Public schools have cropped up near the basin and sections of the road in low areas face the prospect of flooding. Another 1981 like GLOF will cause much more damage,” says Dr Arun Bhakta Shrestha, Climate Change Specialist at ICIMOD.
Nearly 900 houses with a total population of 5,800 will be directly affected if floods of the same magnitude of 1981 GLOF occur again. The figure will go up to 1,653 houses and 10,531 people if flood of higher magnitude takes place.
Around 21 kilometre of the Arniko Highway, two bridges at Khandichaur and Barabise, Bhote Koshi and Sun Koshi hydro power dam and their power houses and hundreds of hectares or agricultural, forest and grass land in the region are also exposed to GLOF risk.
It is estimated, if another GLOF of the magnitude of 1981 occurs now, properties worth US $ 159 million would suffer damage. If the magnitude is higher, the damage would be worth US $ 197 million—much higher than the US $ 4-5 million three decades ago.
There’s more. The 36 MW Upper Bhote Koshi Hydroelectric Project located right beside the highway could be a casualty if another GLOF takes place. Although a warning system could save human lives, the structure could suffer huge damage—affecting power supply for months.
Damage to the highway will affect trade between Nepal and China via the border. Nepal imports readymade garments, blankets, wool, apples and mobiles and exports medicinal herbs, handicrafts, flour, ghee and noodles through this route. Last year imports totalled NRs 10.35 billion while exports were worth NRs 400 million.
But nothing seems to have happened on the ground. Lack of awareness, absence of government policy on constructions along the river basin, poverty and unplanned development seems to have prepared a dangerous cocktail that could see another repeat of 1981 or even worse.
For most of us words like climate change, global warming, ozone depletion and carbon emission have little direct or noticeable impact on our lives. But for residents of Barabise and other settlements along the Arniko Highway they could mean difference between life and death.
