SEOUL: South Korea needs to take pre-emptive measures to combat climate change after the nation's capital Seoul was battered by record-breaking downpours over the last two days.
The capital and its surrounding areas suffered the worst downpour in 115 years and experts warned that the country may witness more extreme weather events caused by climate change.
Casualties from this week's heavy rains have risen to 11 people dead and eight others missing, officials said Thursday.
The Central Disaster and Safety Countermeasures Headquarters said six deaths were reported in Seoul, three in Gyeonggi Province and two in Gangwon Province while three of the eight unaccounted for were from Seoul.
About 3,775 homes and buildings were inundated, most of them in Seoul after 525 mm of rain fell in Seoul from Monday to Wednesday morning, causing numerous flash floods throughout southern Seoul.
Almost 1,000 people from nearly 550 households, mostly from the wider Seoul area, have been moved to local schools and gyms. Another 4,300 people from more than 2,000 households across the country have also been temporarily evacuated.
The Korea Times reports that following a flood response meeting, South Korean President Yoon Suk-yeol apologised to the public for the troubles due to the heavy rainfall and ordered relevant ministries to take immediate measures for a swift recovery.
"We can no longer call such extreme weather abnormal. We may see record-breaking levels again at any time," he said, stressing that the country must map out new measures to cope with worse-than-expected scenarios.
"Dongjak District saw the highest amount of rainfall since the country began tracking precipitation levels in 1907," an official at the Korea Meteorological Administration (KMA) told The Korea Times.
"But we have not included the figure in the official record since the data came from Dongjak District and not from the official weather observation center in Jongno District."
The weather agency also saw the heavy rainfall as somewhat unusual, considering that South Korea's annual rainy season was usually from late June to the end of July.
"The heavy downpour was brought by a rain band caused by a collision between dry, cold air from the north and a warm, humid air band from the south forming in the central region of Korea," the agency official explained.
However, he was cautious in linking the extreme weather to climate change caused by global warming, saying that more data was needed before a link can be established.
Disaster management experts said the unprecedented flooding occurred because the drainage system in Seoul could not handle the sudden increase in volume and they urged the city government to scale up its infrastructure to cope with similar situations in the future.
"Disasters often occur without any warning signs, the very reason why we must be fully prepared in advance," said Kong Ha-sung, a professor of fire and disaster prevention at Woosuk University.
"In order to save more lives and mitigate the impact of disasters, investing in prevention is much more important than relief efforts."
He added that authorities should improve the drainage system especially in Seoul's Gangnam district, as it was geographically vulnerable to floods.
"The neighbourhood near Gangnam subway station is about 10m lower in altitude than surrounding areas, causing the area to flood very quickly. The drainage system in the district can handle only up to 90 to 95 mm of rain per hour," Kong said.
Cho Won-cheol, an emeritus professor of civil engineering at Yonsei University, said he believed that the capital region did not have sustainable drainage infrastructure despite rapid urbanisation.
"Many roads in Seoul do not have proper drainage systems to efficiently collect and remove water runoff in the event of heavy rain or floods. It is regrettable that the importance of ensuring sufficient investment in such infrastructure is often overlooked by the authorities," Cho said.
Meanwhile, Yonhap News reports the Seoul city government saying that medium- and long-term flood prevention measures will be carried out in six flood-prone areas.
Mayor Oh Se-hoon said about 1.5 trillion won (US$1.15 billion) will be spent over the next decade to build six large-scale rainwater storage and drainage facilities, also called deep underground tunnels.
According to the Yonhap report, the underground tunnel project involves building large drain pipes at a depth of up to 50m underground.