A "Great Flood" Out of Nowhere... Growing Fears Over "Glacier Collapses"

[Anchor]

As you saw earlier, this major flood struck abruptly with no rain at all, and its destructive power was far greater than that of a flood caused by heavy rainfall.

How did such a glacial flood occur, and what is the extent of the additional risk? Reporter Seo Donggyun explains in detail.

[Reporter]

Ice in high-altitude regions like the Himalayas forms when more snow accumulates than melts.

However, over the past 30 years, temperatures in Nepal have risen rapidly by 0.02 to 0.16 degrees Celsius annually depending on the region.

Naturally, the surface area of the glaciers has decreased.

They have been disappearing at a rate of 1 to 5 square kilometers every year.

When a glacier collapses, flooding can occur in largely two ways.

First, when massive chunks of ice break off, the ice and rocks swept down together can block a river, creating a natural dam.

As water builds up, this dam can suddenly collapse, leading to a flood.

Weight is being given to the possibility that the recent major flood in Nepal occurred in this manner.

There is another possibility.

Lakes formed by accumulated meltwater from glaciers are called glacial lakes, and when these glacial lakes collapse due to external impacts, they can also trigger flash floods.

According to recent studies, 189 floods of this type have occurred in the Himalayas since 1900, killing some 6,600 people.

The danger is growing increasingly worse.

Over the past 30 years, the surface area of Himalayan glacial lakes has increased by 0.83% annually, with the number reaching around 2,000.

An analysis of about 550 glacial lakes in the border region between China and Nepal showed that 26% of them have a high risk of collapse, according to research results.

Glacier collapses can lead to even faster glacier collapses.

[Kim Baek-min / Professor, Department of Environmental Atmospheric Sciences, Pukyong National University : (Due to warming), snow melts, which reduces the white-colored effect of reflecting sunlight, accelerating global warming twofold or threefold.]

Although it is premature to definitively attribute the cause of this major flood to climate change, it is clear that climate change is increasing potential flood risks.

(Video Editing: Lee Sang-min, Design: Park Chun-woong, Park Tae-young)
※ Please note: This article was translated by AI and may contain errors.