The 'wet snow' that stayed in the water increased the damage of the heavy snow...How dangerous?

■ Host: Anchor Jeong Jin-hyung and Anchor Lee Eun-sol
■ Starring: Yeom Gun-woong, Professor of the Department of Police Fire and Public Administration at Yuwon University

* The text below may differ from the actual broadcast content, so please check the broadcast for more accurate information. Please specify [YTN New Square 8PM] when quoting.

[Anchor]
The heavy snow caused a series of multiple crashes, including the collapse of facilities, throughout the country. As you can see, this also caused casualties. We will take a closer look at the situation of heavy snow damage and how to deal with it. Let's talk to Yeom Gun-woong, a professor of police fire administration at Yuwon University. Please come in. Looking at this time, it seems that the damage was particularly severe in southern Gyeonggi Province. Why do you think the damage was so great when the facility collapsed during the snow removal work and people died one after another?

[Yum Gunwoong]
First of all, if you look at yesterday and today's accidents, there were a lot of collapse and slip accidents. This can only be attributed to the rapid change in weather conditions. The seawater on the west coast of Korea became too warm. So, it was really hot this summer. As a result, the water temperature was about 2-3 degrees higher than usual. So the water temperature is high, but the air in the atmosphere is cold. So, in this situation, there is a temperature difference between air and water temperature in the atmosphere, and this is estimated to be about 25 to 50 degrees. So, since there is a lot of temperature difference, cold air passes through the sea and this comes up from the warm sea. As these air rises, there is a lake effect where snow clouds are created. So, because snow clouds are actively generated and there is an unusually heavy snowfall for November, there is a stagnant low-pressure system that flows from west to east in Korea's atmosphere. It moved from the west coast to the center and inland areas without getting out of it, and it snowed a lot in southern Gyeonggi Province or Gangnam, Seoul. The cumulative snowfall measured by the Korea Meteorological Administration yesterday averaged 18cm in Seoul. But the Seoul Meteorological Observatory is located in Jongno. It's in Songwol-dong, Jongno-gu, and it's about 18cm based on the average here. In fact, in Gwanak-gu, it fell by 40.2cm. But in Seongbuk-gu, it fell about 29cm. So, it fell about 40cm in the Gangnam area of Seoul rather than Gangbuk, and Gyeonggi-do Province also tolerated it, and Suwon fell more than 40cm. So, the damage was great where the snow fell intensively in this area.

[Anchor]
In Gyeonggi-do, you pointed out that it was more than 40cm, but it was operated until the third stage of emergency response, where all available resources were mobilized. I heard it's the first time it's been operated due to heavy snow.

[Yum Gunwoong]
I'm afraid not. It was in operation in 2012. In 2012, the third stage of response to heavy snow was in operation in 2012, but in fact, this time is larger than then. That's why the third stage came back into operation. It responded by mobilizing 2,129 vehicles and 17,000 people. So, as it kept snowing and freezing all night, damage continued, so we used all the vehicles and available resources in Gyeonggi-do to remove snow and save lives. So this response stage occurred because there was a lot of snow that was unusual.

[Anchor]
In fact, it is said that the damage has increased because the snow is wet this time, but the snow can be this dangerous. I don't think it was an opportunity to evoke these new things, but how dangerous should we actually see this practice?

[Yum Gunwoong]
So just because we're building, our eyes don't dry out. But the expression is construction. As I said, it's a wet theory that contains more water than this, but it became a wet theory because it was sprayed in the central part of the country on the west coast. Then, in the end, how much weight or volume does this theory occupy or density, it is three times more than that of construction. It's just three times as much. So, for example, 1km of snow piled up on the same roof. Then, if wet snow accumulates in the same area, 3kg accumulates, and if 1 ton accumulates, it becomes 3 tons. So, if wet snow builds up in the same area, it is under three times the weight pressure, so yesterday's accidents cause the roof of the parking lot to collapse or even the roofs in front of the playground to collapse. So it showed a lot of structures with weak supports acting as bridges collapsed. Therefore, the reason why wet snow is dangerous is that it is actually dense and weighs a lot, so it often leads to collapse accidents. However, the simple distinction between construction and practice theory is that if you push and clean up construction, it goes down quickly. It's all scattered like it's scattered, but I catch the habit. It doesn't get pushed away and doesn't get cleaned up. So the people who first went up to snow removal pulled the wet snow, so it didn't clean well. That's why accidents happen.

[Anchor]
eyes three times heavier Maybe that's why there were a lot of collapse accidents like you told me. There was even an accident where I died while snow removal, what should I be careful about when removing snow?

[Yum Gunwoong]
First of all, moist snow clumps well and does not flow down. Since it has a catchy nature, there were many accidents and many people who were hurt when they heard that it snowed a lot yesterday. But in the end, I think you have to look at the weather conditions. This is because the assumption that we can get this much snow at the end of November.
What I mean is that the temperature on the west coast is rising and snow containing that water can be sprayed this much at the end of November. This is wet snow and can have three times the weight and density. Then, this collapse can happen at any time. In the case of yesterday, this is the first time that such a rumor has fallen, so it can be said that the snow removal was done quickly to prevent the collapse or take such safety measures, but in this situation in the future, such a rumor will come down. And if it snows a lot, it's better to stop snow removal while listening to the weather conditions. Because if the possibility of collapse increases, property damage can be restored, but human damage cannot be recovered. That's why it's better to evacuate quickly. One more trick is to stop snow removal and listen to the snowy situation. If the situation is judged, avoid it and evacuate, but as I said earlier, put a tape around it like a safety control line or write a danger mark on it to prevent it from collapsing. It would be better to prevent additional casualties by doing this or putting a safety fence.

[Anchor]
Then, would it be more appropriate to remove it after a certain amount of snow accumulates?

[Yum Gunwoong]
As I told you before, usually greenhouses and congratulatory speeches have collapsed a lot. But the reason why there was even a collapse this time is that the utility pole collapsed, and this is when the trees fell and the trees hit the utility pole and collapsed. Then, usually, when a tree falls, it's not often collapsed by snow. It snowed a lot this time, and it snowed close to 40cm. And since it weighs more than three times as heavy, trees are just falling down. How hard is the wood, actually. As I said earlier, structures like barns and parking lot entrances are actually very vulnerable to the practice of falling down trees with roots and columns. Then in the end, if this practice falls and a large amount falls, it is best to judge the snow removal work, stop quickly, evacuate, and then take safety measures.

[Anchor]
As you said, if you look at the type of damage, it seems that there were many phenomena such as collapse and collapse. However, there was also a power outage in such apartments and places where many generations lived together. There's also a water cut. There was also a phenomenon where something collapsed on the way, but in fact, if this happens, we have to worry about damage in our daily lives, so how can we be careful?

[Yum Gunwoong]
First of all, you need to be careful of falls. You have to be careful about falls while walking, but when I look at it today, the roads in Seoul and Gyeonggi-do are all well defrosted. But you have to be careful because there's a possibility of black ice at night. It's very likely that icy roads will occur on sidewalks. Because in India, where there are many people, the snow has been removed to some extent, but in places where there are few people, there are still places where snow has been piled up. Then, in this case, the temperature drops at night and the wind blows a lot, increasing the likelihood that it will become ice again. Then you have to go to work tomorrow morning. Then it's very likely that the icy road will be tomorrow morning. So you have to pay attention, especially when it's cold, everyone puts their hands in their pockets, but you should never put your hands in your pockets. Because I can't control my body when I put my hand in my pocket when I'm falling. It can't be avoided, and it's even called a trick. People can turn around and avoid it, but they can't even do that. So I think it would be good to prepare gloves in advance without putting your hands in your pockets like this. Next, check if the floor is icy and walk around. In particular, high heels or shoes should never be worn because the floor is slippery. So, for example, I think it would be better to wear sneakers or hiking boots with some bumps on the floor or patterns for the time being. You have to shake off the eyes on the bottom of your shoes because they get on your shoes. So, since it's wet here, you need to remove the water and do this to prevent a fall accident. Then, if a power outage and a water cut accident occur like this. This is actually an irresistible situation, but assuming that you can be in this situation, get water in advance and prepare bottled water. Especially at night, the elderly and children can be cold, and this problem can occur, so you should take measures to keep warm. It is better to take out thick blankets in advance, wear thick padded pants, quilted pants, or fleece pants, or wear an innerwear and wait for water supply or electricity to come in while keeping warm.

[Anchor]
I think it's going to be a very cold and cold week for everyone. One of the things you mentioned earlier is black ice. The 53-car crash also occurred in Wonju, Gangwon-do. How dangerous is this considered to be the cause of the big accident?

[Yum Gunwoong]
So you can think of the braking distance as three times longer. Considering that the braking is just right on ordinary asphalt when we catch it, if black ice occurs now, it will be pushed forward three times even though the brake is applied. So, if you look at the 53-car crash in Wonju yesterday, you keep thinking about why the car keeps crashing, but this is a situation where the car keeps getting pushed even if the brakes are applied. If you look at it yesterday, it was snowing here, but it became icy as the snow melted. So in the end, it's a situation where it's turned into black ice. Black ice occurs especially at night, and when the temperature is below zero, and when the wind blows a lot, snow is removed and melted again during the day. That's why you spray calcium chloride. Calcium chloride and the vehicle wheels rotate together, resulting in a slush effect, which melts the snow and then freezes again at night. But we drive while looking at the snow. So rather, people are slowing down and paying attention, and this black ice looks just like a regular asphalt road. As a result, you just get the illusion that it won't be slippery here, and sometimes you speed up. Then, the braking distance of ice and ice is longer than that of snow. So, with this braking distance three times longer, the possibility of continuous crashes increases in the end. As I said earlier, there is a high possibility of black ice occurring at night. In addition, the entrance of the tunnel, the bridge connection, up and down the overpass, and the shaded areas, especially those with less traffic, are likely to have black ice tomorrow, so drive carefully and first, we are under the Road Traffic Act, but if the snow falls more than 20cm, it is said to slow down by more than 50%. So what are you talking about? If we went at the speed limit of 60km, that means you have to go at 30km. If you've traveled 50km, that means you have to travel 25km. So, to tell you the 22nd law, you have to take twice the distance between the vehicle and the distance from the car in front of you, when it snows this much. And then you have to double the speed again. I would like to advise you to reduce the speed by 50% and then double the distance from the car in front of you.

[Anchor]
In a slippery situation and a long braking distance, it is better to consider these things and consider the safety distance sufficiently. You said you need to slow down more, are there any other ways? Something related to braking.

[Yum Gunwoong]
First of all, there are cases where you turn the handle because you are embarrassed at first. However, as I said earlier, you have to open the speed more than twice at a low speed, reduce the speed more than twice, and go around in this situation, but you can operate the handle in the direction of sliding within 30km. What I'm saying is that when you slip, people get embarrassed and manipulate the steering wheel on the other hand. But you have to leave the handle as it is in the direction of sliding. If you leave it, there is a trick to breaking it. You have to lightly apply the brakes several times. Because if you're in a hurry, you step on it. Then, you grab the brake, but the car turns.

[Anchor]
What's the reason?

[Yum Gunwoong]
This is because if you brake, the tire is caught by the friction force of the road surface. But there's no friction on the road right now. So, the brake is held, but the car goes out or turns around. So in the end, it's most important to drive at a low speed and take a safe distance, but if there's a risk of such a black ice accident, you have to apply the brakes several times. Then, in the direction of the steering wheel sliding. Never turn in the opposite direction and operate it as it is. But if the car stops or there could be an accident. Then, it is recommended that you drive slowly on the shoulder and turn on the emergency light while driving slowly on the shoulder to prevent other additional accidents because vehicles can continue to crash like a 53-car collision and a Wonju accident. But if there's a spray on the vehicle, If you have something like that, it would actually be better to take it in advance and spray it.

[Anchor]
Let's stop here. I talked with Yoo Won University, a professor of police fire administration. Thank you for talking today.