WEATHER NEWS: As record-setting heat blasts Pakistan, a glacial lake floods village
Record-high April temperatures over Pakistan melted glaciers faster than normal, triggering a flash flood Saturday in a village in the northern region of the country that wiped out part of a key bridge and damaged homes and buildings.
The event, known as a glacial lake outburst flood, occurs when water is suddenly released from a glacial lake due to a dam failure or breach. Warmtemperatures over the past month accelerated snow and ice melt near an ice-dammed lake by Shishpar Glacier, near Mount Shishpar, increasing the lake’s volume and likely causing the breach.
Authorities are providing food, winterized tents and other necessities to affected families in Pakistan’s Hunza District.
The flooding that damaged the Karakoram Highway followed Pakistan’s hottest April on record since 1961, intensified by human-caused climate change. Over the past month, heat waves have baked the Indian subcontinent.
Several weather stations set record highs for April: Jacobabad hit its warmest daytime temperature at 120 degrees Fahrenheit (49 Celsius) on April 30; the Karachi Airport reached its warmest nighttime temperature at 84.9 degrees Fahrenheit (29.4 Celsius), also on April 30.
While most glacial lakes typically form in May, rapid snowmelt caused the lake near Shishpar to form a month earlier in April. Over the past 20 days, the lake expanded by 40 percent. Pakistan’s minister for climate change warned that the country’s vulnerability to flooding is high due to the heat wave hitting the region.
The lake was growing fast while the snow cover was melting very quickly too! Time series of Landsat and Sentinel-2 images from 26 Mar to 05 May. pic.twitter.com/KYCFrgZ86i
The Gilgit-Baltistan Disaster Management Authority saidthe lake discharged around 10,000 cubic feet per second, enough to sweep away scaffolding on a portion of the Hassanabad bridge. Authorities created an alternate route around the region. The National Highway Authority announced it will install a temporary bridge within a month, while construction of a new bridge will be completed in six to eight months.
Two power plants in Hassanabad were also reportedly swept away by the flood.
Over a dozen houses, a community center, among properties worth tens of millions lost in #Hasanabad village of #Hunza, within a matter of hours.
Glacial floods pose an increasing hazard in Pakistan’s northern mountainous regions as global temperatures rise. As mountain glaciers rapidly melt, more than 3,000 glacial lakes have developed in the highly glaciated northern areas of Gilgit-Baltistan and Khyber Pakhtunkhwa. According to the United Nations, 33 of those lakes are prone to hazardous flooding.
Researchers have studied the Shishpar lake due to its potential flooding risk. The lake near Shishpar glacier appeared only about four or five years ago. In 2017, the Shishpar glacier began surging, or rapidly moving forward. As it advanced, it blocked a river by the nearby Muchuhar glacier. The meltwater from the Muchuhar glacier began collecting in a pool until water levels rose to form an ice-dammed lake.
Ice-dammed lakes are typically unstable, but most slowly drain over the course of a season without creating major problems. However, sometimes ice dams can collapse suddenly, or lake water spills over the dam, causing floods. In 2019, the lake reached its maximum area and breached the dam, damagingpart of the Karakoram Highway.
Hunza Deputy Commissioner Muhammad Usman Ali said his region has routinely been hit by floods caused by glacial melt since 2018.
“Luckily we don’t have that many residents in the areas surrounding the glacial lake,” and they had time to move to avoid the most recent flooding and avoid any loss of life, he said. However, he added, the waters destroyed agricultural land, power projects and some houses.
“This glacier melting is worrisome because it’s now happening on an almost annual basis,” he said, noting that many regions of the country are affected. “All of this is related to climate change.”
More flooding is feared when temperatures are expected to spike again later this week. Extremely hot weather is predicted for Pakistan this week, with maximum temperatures as high as 122 degrees (50 Celsius). The highest temperatures are anticipated Wednesday and Thursday.
As greenhouse gas emissions from fossil fuel burning increase global temperatures, Pakistan has warmed around 2.1 degrees Fahrenheit (1.2 Celsius) since the preindustrial era. Projections from Berkeley Earth show the country could warm 6.3 degrees Fahrenheit (3.5 Celsius of warming) by 2100, assuming carbon emissions are stabilized in the near future and then slowly decline.
“Pakistan has the highest number of glaciers outside the polar region and many are losing mass due to high global temperatures,” tweeted Sherry Rehman, a Pakistani senator. We need global leaders to reduce emissions.”
Shaiq Hussain in Islamabad, Pakistan, contributed to this report.