Typhoon 'Khanun' Landing on the Korean Peninsula Brings Extreme Rainfall... Must Prevent 'Underground Space Disasters'

Prevent Recurrence of Pohang Underground Parking Lot and Osong Underpass Disasters
"Beware of Tributary Water Levels and Avoid Using Underground Spaces"

Typhoon Khanun, the 6th typhoon expected to vertically cross the Korean Peninsula, made landfall in the southern region on the morning of the 10th, raising calls for preparedness regarding underground spaces that suffered casualties from the recent heavy rain. Underground spaces such as underpasses and underground parking lots are prone to flooding due to their lower elevation compared to surrounding areas, and evacuation options are limited, increasing the risk of severe damage.

According to the Korea Meteorological Administration, Khanun made landfall near Geoje, Gyeongnam, around 9:20 a.m. on the same day. Moving northward, Khanun is expected to pass through western Gyeongsang, northern Chungbuk, and eastern Gyeonggi before crossing into North Korea early on the 11th.

The problem is that Typhoon Khanun is expected to bring heavy rainfall. As of 9 a.m., rainfall is pouring at a rate of 30 to 60 mm per hour mainly along the Gyeongsang coast, and 10 to 30 mm per hour in Gangwon Yeongdong.

Extreme heavy rain is also expected in some areas such as Gangwon Yeongdong, the Gyeongsang coastal region, and the inland western Gyeongsang area. Extreme heavy rain refers to rainfall that simultaneously meets the criteria of '50 mm in one hour' and '90 mm in three hours.'

In particular, Khanun's movement speed is expected to slow down to about 20 km/h, meaning it will linger over the Korean Peninsula longer and potentially cause significant damage.

Typhoon No. 6 'Khanun' approached Busan on the afternoon of the 9th, and the Choryang Underpass in Dong-gu, Busan, is being closed.
[Image provided by Busan Police Agency] [Image source: Yonhap News]

Accordingly, preparations to prevent flooding damage in underground spaces seem necessary. Underground parking lots and underpasses are low-lying areas where water quickly accumulates during heavy rain. The risk increases further if nearby tributaries overflow.

In September last year, when Typhoon Hinnamnor swept through, seven residents who came out to move their vehicles died in an underground parking lot of an apartment complex in Pohang, Gyeongbuk. The cause was water from the nearby Naengcheon stream flooding into the underground parking lot.

One of the main causes of the Osong Gungpyeong No. 2 Underpass disaster, which claimed 14 lives, was the collapse of the temporary embankment of the Miho Stream. On the 15th of last month, the temporary embankment of Miho Stream Bridge collapsed, releasing 60,000 tons of water, and the underpass was filled with water within three minutes.

Professor Jung Chang-sam of the Department of Smart Construction Disaster Prevention at Induk University emphasized the need to inspect nearby tributaries to prevent similar flooding disasters in underground spaces.

Professor Jung appeared on MBC Radio's 'Kim Jong-bae's Focus' on the same day and said, "When tributaries overflow, underground spaces next to them can suddenly be flooded with river water, causing incidents like the Gungpyeong underpass disaster, so caution is necessary. These tributaries can fill and overflow within about four to five hours."

He added, "People living near tributaries should pay attention to the water level of the tributaries and absolutely avoid using underground spaces."

In regions currently under the influence of the typhoon, vehicle traffic in underpasses is being restricted. As of 8 a.m., in Changwon, Gyeongnam, where rainfall is 40 to 60 mm per hour, traffic in 20 underpasses has been banned, and in Pohang, Gyeongbuk, some underpasses such as Sangdo Underpass and Baetmeori Underpass are also being controlled.

Busan, where a tragic accident occurred in early 2020 at the Choryang No. 1 Underpass resulting in three deaths, is also restricting access to the Choryang No. 1 Underpass.

This content was produced with the assistance of AI translation services.