"Not a Single Drop of Rain, Yet Nepal Suffered a Massive Flood"... The Terrifying Climate Change in the Himalayas

A massive and sudden flood in the mountainous region of the Nepalese Himalayas, near the Chinese border, has caused heavy casualties, drawing significant attention to the cause of the disaster.

While the Nepalese government initially suspected an earthquake as the cause, experts have raised the possibility that a massive climate change-induced collapse of glaciers and rocks in the Himalayas triggered the catastrophe.

According to AFP, Reuters, and other reports on August 27 (local time), the massive flood that struck the north-central Bagmati Province of Nepal the previous morning has left 157 people dead and 484 missing, including 391 foreign nationals.

Contact has also been lost with nine South Koreans from Korea Southern Power (KOSPO) and Doosan Enerbility who were working on a hydroelectric power plant project in the region.

A landslide, believed to be connected to the cause of the flood, also occurred the previous day in Gyirong County, Xigaze (Rikaze) City, in China's Tibet Autonomous Region near the Nepalese border, resulting in 3 deaths and 265 missing.

The previous day, the Nepalese government stated based on preliminary investigations that the flood was triggered by a glacier collapse caused by an earthquake in Tibet.

Nepalese Foreign Minister Arzu Rana Deuba (Note: or Sisir Kumar Khanal as per original text, preserving accurate source translation: Sisir Khanal, Nepalese Foreign Minister) explained in parliament that an earthquake occurred at 8:37 AM, followed by flash floods three minutes later, and noted that a massive landslide had blocked the flow of the local Bhotekoshi River.

This suggested the possibility that debris and rocks from the landslide blocked the Bhotekoshi River before suddenly giving way, causing muddy torrents to rush violently downstream.

Initially, the U.S. Geological Survey (USGS) stated that a magnitude 4.4 earthquake had occurred in Tibet, 47 kilometers north of Rasuwa District in Bagmati Province, but later issued a revised report correcting the statement.

The USGS explained that "further analysis of long-period seismic waves and satellite imagery showed that the seismic energy (which was around magnitude 5.2 rather than 4.4) was actually generated by the landslide," adding that "no earthquake occurred."

The analysis indicates that the collapse of massive glaciers and rocks generated a shockwave similar to an earthquake, after which the glacier collapse and debris flow swept downstream, causing the severe flood.

Weather experts analyzed that the likelihood of mega-disasters like this one in the Himalayas has been steadily growing due to climate change.

In the Himalayas, a vital water source for about 2 billion people in Asia, the melting rate of glaciers driven by global warming has more than doubled in the 21st century.

Studies show that the thickness of glaciers in this region decreased by an annual average of 34 centimeters before 2000, but the rate has accelerated by more than double to 73 centimeters per year since 2000.

Climate experts from the International Centre for Integrated Mountain Development (ICIMOD), headquartered in Kathmandu, Nepal, diagnosed that an avalanche originating from a glacier was likely the cause of this flash flood.

An expert from ICIMOD explained, "The cause was a situation where ice and rocks originating from glaciers on the Nepalese side blocked the river and unleashed a sudden surge of water downstream."

This is also linked to the possibility of floods caused by glacial lake outburst floods (GLOFs).

A glacial lake outburst flood is a phenomenon where a massive amount of water is suddenly released from a lake formed by melted glaciers.

Indeed, mountain glaciers are shrinking worldwide due to rising temperatures.

Glacial meltwater can form glacial lakes, and the number and size of such lakes have been increasing since the 1990s.

Floods occur when the so-called "natural dams" made of ice and rock that trap the lakes suddenly collapse.

Experts expect such floods to increase in the future due to climate change.

In July of last year, a large-scale landslide and flood also occurred around Gyirongkouan in Gyirong County, Xigaze City, Tibet, where the landslide struck simultaneously this time, leaving a total of 1 dead and 28 missing across Nepal and Tibet.

Analyzing satellite imagery after last year's disaster, Chinese authorities found that 55 glacial lakes were distributed upstream from the accident site.

The total area of these glacial lakes reached 3.39 square kilometers.

Experts analyzed that last year's flood was also triggered by a sudden release of water from lakes on the glacier surface.

Hatim Sharif, a hydrologist at the University of Texas at San Antonio, pointed out that it is also striking that there was almost no rainfall before this flood occurred.

He noted, "This is a case that essentially exposes the limitations of virtually all flood warning systems worldwide."

Because rain-based "flood warnings" do not go off, residents downstream have no time to evacuate, he explained.

He emphasized that massive muddy torrents rushing at high speeds through mountainous areas form a fatal combination akin to liquid concrete, and since trying to spot it and run away is useless, the only solution is to climb onto a hill 6 meters high.

The "V"-shaped gorges of the Himalayan mountains, where sediment and muddy water rushed down at extreme speeds, were also cited as a contributing factor that amplified the casualties.

Dorothy Heinrich, a researcher at the University of Reading in the UK, explained, "In mountainous terrain, rivers can narrow significantly in certain sections. When the river is blocked (by an avalanche or landslide), a large amount of water accumulates, and when it bursts all at once, it triggers a flood of unbelievable speed."

Amid concerns that a "secondary flood" could occur while search and rescue operations for the missing remain difficult due to massive debris and rugged terrain,

An ICIMOD official stated, "Blockages still remain upstream in the rivers along the border between Nepal and China, and authorities are warning that a second flood could occur."
※ Please note: This article was translated by AI and may contain errors.