The previously dry Barsuwat riverbed in Ishkoman, Pakistan, was inundated with flood waters from the melting Barsuwat glacier last month. The water triggered landslides that blocked the flow of the Immit River and formed an artificial lake. On July 18, a glacier lake outburst flood (GLOF) event originating from the artificial lake produced significant flooding in nearby villages in the Ishkoman Valley of the Ghizer district, Gilgit-Baltistan. Two people were killed during the initial rush of floodwaters, and around 1,000 people were evacuated to safer areas ahead of the GLOF by Community Emergency Response Teams (CERTs).
During the GLOF, the melting glacier released debris, including mud and stones, which damaged over 40 houses and cut off roadway access to upwards of 10 local villages. Part of the Karakoram Highway became submerged, while some smaller roads were washed away along with over a dozen vehicles and hundreds of cattle in the upstream areas.
The Barsuwat glacier has been melting more rapidly than normal due to a May heat wave in the region that killed 65 people in Karachi, Pakistan. According to Dawn, an online Pakistani newspaper, the deputy commissioner of Ghizer, Shuja Alam, said that the glacier started melting on July 17, the night before the flooding event, at about 7 p.m. The floodwaters have since waned as the ice and debris have melted and washed away.
The evacuation of the villagers prior to the GLOF event was made possible by a community-based flood early warning system in Gilgit Baltistan developed by the International Centre for Integrated Mountain Development (ICIMOD), an organization that monitors glacier melt and the dams that can lead to lake formation and flooding.
Earlier in April, ICIMOD’s Director General David Molden had pledged “ongoing support to Pakistan’s government and community institutions” and highlighted the organization’s partnership in disaster risk management in Gilgit Baltistan as key to enabling locals to respond to the consequences of climate change, including an increase in glacial lakes and flooding events.
ICIMOD is currently collaborating with the Gilgit Baltistan Disaster Management Authority and the Aga Khan Agency for Habitat on disaster risk management in the area. These kinds of collaborations are becoming increasingly necessary as disasters like the one in July become more common. “Today, the fast melting glaciers pose the greatest disaster risk to Gilgit-Baltistan and Chitral. I see massive deforestation that the region has experienced over the decades as a major factor behind this situation,” Ghulam Rasul, director general of Pakistan Meteorological Department (PMD), told Dawn.
However, Ken Hewitt, professor emeritus of the department of geography and environmental studies at Wilfrid Laurier University, who spent his career studying glaciers in Northern Pakistan, warns of a greater threat to the region. “Bigger risks come from ice dams, of which there have been seven or more in the upper Ishkoman (Karambar tributary) since late 19th century,” he told GlacierHub.
He added that there is potential for one of these ice dams and resulting GLOFs from a recent advance of Chillinji Glacier. “Its terminus has advanced across the Karambar River, but not sealed a dam to date—though it has in the past,” Hewitt said.
Accumulation area of the debris flow in the Ishkoman River valley (Pakistan). Sentinel 2A pic.twitter.com/ASibEJdBvs
— Михаил Докукин (@inrushmd) July 22, 2018
News outlets in Pakistan have likened the July 2018 artificial lake formation in Ishkoman to the formation of Attabad Lake in Hunza River Valley, Pakistan, in January 2010. Attabad Lake was created after a natural rock landslide buried the village of Attabad and dammed the Hunza River. The lake grew to 21 kilometers across and over 109 meters deep.
The Ishkoman Valley lake is different, however, in that it does not have the same blockage characteristics that could withstand warming temperatures and height of the rising waters to form a permanent lake.
As the region looks to the future, Hewitt is keeping his eye on the Hasanabad Glacier in Hunza, about 50 kilometers downstream from Attabad, which is currently undergoing a massive surge. “It had the longest, fastest surge on record a century ago and is a unique glacier in other ways,” he said. He remains doubtful it will reach the Hunza River, but he cautions that it could form a dam on its large tributary, risking another GLOF in the region.