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An underground parking lot, a space we are familiar with, can quickly turn into a dangerous place.

Last month, when it rained heavily in the metropolitan area, the underground parking lot was flooded and one person died.



Reporter Ha Jeong-yeon pointed out what countermeasures would be needed to avoid repeating such damage.



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Rainwater pouring down like a waterfall from the entrance to the underground parking lot.



It swirls like a whirlpool between cars lined up towards the exit.



The 11th typhoon 'Hinnamno' caused the greatest casualties in the underground parking lot of the Pohang apartment complex.



Last month, when record heavy rain fell in the metropolitan area for the first time in 115 years, a man in his 40s could not get out of the underground parking lot of a building in Gangnam and eventually lost his life.



It is a recent repetition of human casualties in underground parking lots whenever major disasters, especially rain damage, are large.



Due to the lack of parking space, the trend is to create deep underground parking lots, experts fear that these underground parking lots can become a serious hazard area during heavy rains.



The entrance to the underground parking lot is wide open in contact with the ground, and it slopes downwards, allowing a lot of water to flow in at high speed.



[Won Cheol Won/Professor of Civil Engineering, Yonsei University: If it is steep, it goes quickly when the water enters, that is the key.

(force) is proportional to the square of the speed.

If water enters the underground parking lot along the slope of about 10cm, even 10cm is a huge amount of energy...

.]



Also, because there are several cars parked there, a vortex, or whirlpool, is created between them.



Even drainage is not easy, so when water starts to fill up, it becomes a dangerous situation.



As a result of an empirical test conducted by the National Institute of Disaster and Safety, it was difficult to evacuate from the underground space because of the current even when the water reached the adult shin level.



And it came to the conclusion that it would be impossible for both men and women to evacuate if the water filled up to just below her knees.



Opening the door itself is impossible because of the water pressure.



For this reason, it is safest to get out of the underground parking lot right away if the water starts to fill.



Installing a shroud at the entrance to the parking lot is considered an effective alternative.



However, at present, only those areas where flood damage is a concern are obligated to install the shrouds in the underground parking lot.



[Lee Young-joo/Professor of Fire and Disaster Prevention Department, Seoul National University: I want to install it, it would be much more effective to support these parts in terms of technology and cost so that they can easily install it.] Increasing



the capacity of the drain pump installed in the underground parking lot It is also suggested as a way to reduce risk.



(Video coverage: Park Dae-young, video editing: Lee Seung-hee)