Japan’s 400 Kilometre Tsunami Shield 

Can't believe that it's been 10 years since the tsunami. It feels like those 10 years just flew by.

I actually like the idea of building forest walls along the coastline. One force of nature can be efficiently tackled with another form of nature. Even mangroves are a brilliant solution but i dnt knw if they are fit for Japan's climate.

This was a very well researched video! As someone lucky to live on Japan's east coast, I've traversed almost the entire length of the tsunami shield over the years. The locals seem to have mixed feelings on them, many sacrificing sea views for safety. The government didn't give many towns and villages much choice in the mater unfortunately and in my view, they've gone too far and built too many. Just last week I drove passed a beautiful beach that had no houses or villagers nearby, but the entire area has been smothered in concrete. Still, for the most part the reconstruction in Fukushima, Miyagi and Iwate has been impressive and many locals are optimistic for the future, despite the nightmare they endured.

In Chile, after the 2010 earthquake and tsunami, the aproach in the city of Constitución was to build large forest areas in the coasts to laminate the water (and also create new green areas)

I wonder if they could make a feature out of the walls - creating a raised embankment on the land side so that the view can be enjoyed again, mainly as public parkland or as private enterprise leisure districts. I’d imagine that amount of earth against the walls would also help reinforce them

I live in Japan and was driving along the Sanriku coast last week. It really is remarkable how far Japan has come in 10 years.

The 2011 Tsunami hits me hard, emotionally, every time I hear about it. I was on Maui during that, and we were terrified that we'd get hit by the tsunami. Thankfully we didn't. My heart goes out to Japan.

Trump: I’m going to build a wall Japan: hold my sushi.

I just finished watching the video about the wooden skyscrapers. I just love the B1M, they always have great video

"Be like water" is a martial arts tenet for good reason. No matter its state, it will find a way to create and destroy.

I really enjoyed reading through the innovative and creative solutions mooted in the comments. It's great to see such discussion stimulated on big engineering projects. A couple of broad themes I noticed we're 1) build a concave/wave return wall and 2) the issue of sea level rise. 3) the use of trees etc. With 1), concave walls with wave return crowns and similar are designed to reflect wind wave energy back seaward. The reason this wouldn't work in a tsunami is that a tsunami is a very very long wave (km in length) in comparison to a wind wave (10s of metres in length). Thus the wave energy is spread out over a huge length. This is why the wave takes 10/20 minutes to inundate before the water begins to recede. It is analogous to a open channel flow like a river in a continuously rising flood condition. So wave energy reflection, which can also rely on the wave breaking to some extent, is not applicable here. 2) sea level rise. The point is that the current infrastructure is built on a known mean sea level. Once we start getting the SLR effects then such infrastructure might not be able to perform its function as well. Here, a 15 m tsunami wall may then be only 14.5 or 14 m in the future. This strikes at the core of the debate: do we build hard sea defences in a 'hold the line' approach or do we retreat from the shore line completely, or do we use natural defences or a combination thereof. 3)On mangroves and forests. It's proven for hurricanes/typhoons and storm surges that these can help a lot. But it's less clear on tsunami. Again because of its open channel flow like behaviour. The tohoku tsunami of 2011 resulted in a lot of said trees becoming floating missiles. Some of our experiments also showed that the flow constriction effect (reducing the flow area by adding obstacles) can result in higher flow velocities through the remainder of the area. There's much work to be done in this area still.

Respect ✊Japan 🇯🇵

Fukushima almost failed safe. But for the location of the back-up generators and heat-exchangers, there would not have been a meltdown. The plant survived the M9 earthquake, but it was the size of the tsunami, (nobody imagined it could be that big), which overcame the back-up systems. Nuclear power is pretty safe, built on modern systems, away from seismic areas, it is highly unlikely a Fukushima MK2 would happen again. The tsunami killed way more people, over 20000, than the meltdown, less than 600.

Just get 🇳🇱 Dutch and 🇯🇵Japanese engineers around a table and sea flooding problems are no more!

I still can't believe they put the Fukushima emergency generators on the ground floor and not on the roof. How did they not see this coming?

They should make three 50 meter tall walls and call it: Wall Maria, Wall Rose and Wall Sina.

Japan is just one incredible country!🤩

Regardless of what they did in the past. Modern Japan is a great aspiration for the world to look up to.

Been a long time watcher but subscribed recently and im addicted lol.

Love your content guys.... Rarely disappointed, thanks4posting 👍

Hey the channel reached 2 million subs, let's go!

Thanks for this, great video as always😀😃

Thank you for the video and the research!

One item not mentioned here is that not only was the tsunami taller than the wall, but that the subduction caused by the fault's slippage LOWERED THE WALL ITSELF by about 2 feet.

Love your work... Keep making such interesting videos 💥

Great video as always!

I love this video! It really is amazing and I love it! Thanks B1M for such wonderful videos

Japan always has something incredible. The more I see, more I learn.

why didn't they make the inside of the wall a ramp like they do in denmark so it looks more like a hill from the inside. it would still block the view of the ocean but from the village it would look like any mountain side village surrounded by hills and forest.

I was there in 2011. That was nuts. I mean I was closer to the west coast than the east but I felt that earthquake and I was there during that radioactive crises. 😵‍💫

Thank you for sharing this.

Japan need the "Founding Titan"

omgomgomg new B1M video!!

Dr. David McGovern has a super cool vibe :) He looks and sounds like he would be super fun to talk to over a cup of coffee. Nice video.

You make the best videos. The amount of effort on Research for this video is great.

This channel is marvelous

I love this video B1M, I visited Japan and the Fukushima area, as well as had a private tour because I studied it and was fascinated, the most incredible thing was seeing the power the tsunami had, I stood ontop of a seawall and saw it had still damaged the first 2 stories of the building behind me, I saw concrete cut by the power it was incredible and fascinating!

It might be a different scale to the construction this channel normally features, but could you do a video on bicycle highways in Europe? Or just cycling infra in general?

Wow wonderful subject. Nice presentation. Sir.

Hasn’t been a 9.0 or higher Earthquake since 2011. A monster in the making, only time.

Netherlands:Take Notes,Take Notes

Your content is amazing. You deserve every bit of success you have achieved!

Anybody else excited the B1M is at 2m subs! Great job fellas

Congratulations for Completing 2 Million subscribers..Many more to come

You might say "the Great Wall of Japan"

B1M always make high quality videos. Very informative and interesting as well 👍

5:50 Very important information and good idea

Fantastically made video.

I recommend your channel to everyone I meet ❤

Nothing is more powerful than Mother Nature

Thank you for sharing.

Excellent overview of problems and solutions!

The problem is that most of these calamities evolve over time. I love the artificial cliff suggestion but I want to imagine how much earth Japan can fill to spread across 400 km of shoreline.. Well researched video as always.

Your videos always get a thumbs up at the start because i know whatever is coming, it will be excellent!!! Cheers Ausgranny 🇦🇺🇦🇺👍👍👍👍👍

Waves: 15 meters Wall: 14.7 meters

Man I love this channel

It needs to be longer! Around Nagoya and Wakayama and Kochi

Great!

Another great presentation, thanks 😃👌👌👏👏👏👏

Nice one. Thanks for this piece of information 🙂

a lot of ppl here in Japan say it's better to just live somewhere else rather than building a wall that blocks the beautiful ocean view

What a beautiful video this was. It reminded me on my own experiences with the ocean and how I nearly fell to its tricks and power. Yet I still find it fascinating how Japan went to it head first to atleast have a defense because it could happen any day again. I was always thinking : „why don’t they just build huge walls to protect themselves from these tsunamis because the world knows for damn sure Japan will probably go down from natural catastrophies such as Typhoons, seasons with huge amounts of rainfall, Tsunamis, earthquakes and so on.“ (Sadly half of it happens yearly to them) This video gave me the clear answer I wasn’t thinking about. In a Country where citizens work their asses off to survive and get food on the table for their families loose one more important thing they’re attached to… the sea, the ocean. The view and smell, the cold breeze on a warm sunny day straight from the ocean. Everything combined gives us a sign of peace in our hearts, which gets completely stolen from big walls. So what are we going to do? Plant forests over forests? Build larger wall systems ? Escape and flee from the shore lines? In my opinion there’s only one thing you can do against nature : Work with nature. Walls are straight answers against it while planting trees and creating big green parks would only help against said catastrophies and for the people living there mentally. Fear of death always scares us and drifts us apart from the ocean. I, myself was caught in such huge waves once and drifted, nearly forced away by pure pressure and waves. How did I manage to get back and survive? I had no power, my legs stopped moving. All I had was a ball that I tried to get back before it gets lost to the waves pushing it back. I pushed my chin over the ball knowing it couldn’t sink and would always push itself upwards and I slowly paddled with one arm while I tried to keep my head on the ball with my other arm. After 5 to 10 minutes everyone realized I was in danger and immediately swam to me and helped me to get back to safety. Later on a very smart guy told me I was around 500 meters out (which I can kind of agree on because when I started to swim back everyone suddenly looked like little ants far away running around on the sand) Am I scared of the ocean now? Hell no. I even got more interested into diving. I started to respect the ocean and it‘s power, and now I know how I can survive from it. That’s how Japan is doing it right now. They failed, put themselves back up, respecting it even more than before and trying to find ways to never let it happen again. I hope they find a good natural way so everyone is happy and is able to feel safe again. Amen.

This youtube channel is good! glad to discover it

1:20 "World Leader Of Coastal Engineering" Netherlands : ***BRUH***

A few things... When building sea walls, instead of just tall thin wall - infill the land behind. This would raise the ground level and enable people to still see the sea. There could be a 500m wide park along the top of the infill behind the wall. Another consideration would be to build a break water wall ~1 to 2+km away from the coast. It would prevent, slow, delay, the oncoming wave from pulling back the coastal water that the wave uses to increase height. When the tube and sewer system was build along the Thames, the wall was build, the sewer, underground trains tunnels, and services etc. It moved the side of Thames. This has been done before so can be adjusted to suit the topography. Additionally, there are no outlet doors on the sea walls. So any water that does go over the top or around the wall, can pass back out to sea without puddling, pooling on the land side of the wall. Similar to the Old over flow doors on the London Sewer System that dump raw sewerage into the Thames when it is too full (rain etc). No sea water in but over flowed water can exist. The nuclear plant would not have exploded IF power had continued to run the pumps. The US Navy had a ship running the pumps. It was removed because it was being contaminated with radiation. The ship could have remained and when a ready steady stable power supply was connected - then move the ship and decommission it. The US Govt put the value of a ship above the need for power for the safety of the facility!

Deep rooted trees do a wonderful job on mitigating a tsunamis effects. It´s a great idea.

Idk how this popped up for me, but I am happy it did. Amazing video! Would be interesting to see a geo-wall. It may help and would be less of an eyesore than a concrete wall for the locals.

Quality videos al always

in some regions near by sea In sendai city, people must not build homes. the areas are flat and if tsunami comes, inhabitants cannot escape...

These walls are such a eye-saw! Why didn’t they used the 12 billion to relocated lower valley based towns up to higher ground and use the valleys for farming, sport facilities and non home or office use. I feel for the communities that now can’t look out to sea anymore.

Well, that makes the coastline beautiful and enjoyable.

I appreciate the fact that I have the same rice cooker as Dr. David McGovern 2:30

The forest wall idea has merit if the trees can grow large enough to absorb a portion of the tremendous impact a tsunami brings. A series of earthen berms running in parallel with the shoreline might reduce some of that impact as well.

How do you get to know about these constructions in the first place, I mean from where do you get your video ideas? I am a video editor and I really like and enjoy your content, is there any chance that I get to work with you? @The b1m

This didn't feel like the usual B1M videos. Missed the technical side of construction - no softwares/schematics, interviews of the construction company/workers, the machinery involved, etc. Not complaining, maybe just a little, but that's the reason I love this channel and subscribed to it. ✌🏼

Thanks for making a video about important buildings not just Arab vanity projects

I haven’t watched it yet but this is one of my favourite channels, your videos are amazing Hi from Australia

They should have just covered the distance with weetabix they would soak up any tsunami.

Спасибо!

Love your videos and indepth knowledge and history knowledge

I’m loving that you’re getting more primary source interviews in your videos. The quality is top notch!

I admit I always wish you had short videos and then a longer detailed option. I would love to hear more about the thinking on issues like this from your B1M point of view.

Great education, thanks

great vid

Honestly when is B1M going to do a video about the work I have done in my bathroom??

Yet another great video, although there was one important item that wasn't mentioned. It wasn't just the height of the tsunami that caused issues. The land subsided quite a bit from the earthquake while at the same time the sea bed rose. Land subsidence in some areas was 2 to 3 feet (.6 to 1 meters) while the seabed rose almost 10 feet (3 meters) in some areas. Interestingly, some areas of Honshu have recovered the lost height. This subsidence and sea bed rise affected the tsunami protection and in a few areas allowed the protection to be over topped.

I am sure they didn't name the effort "Project Canute" because, well, you know....

This channel is top notch

A total eyesore. You'd think someone would do something esthetically pleasing, especially in Japan

It's always weird when people get smart and start talking about the "cost" of a literal life-saving structure. Tell me how much a human life cost if you wanna talk about disaster defense.

This video is so interesting 🙌

The moment when your city show up in B1M video, albeit only for a few seconds.. 😁

i don't thing it will stop a ship being driven by a tsunami there go's the wall

Build to protect the city and reduce the impact...but it doesn't mean that you don't need to escape...count for the worst ..

amazing!! 🤩

Glad we had the expert on tsunamis and fluid mechanics come in

1:49 That pictogram needs to run the other way. Took me several seconds even to see the arrow.

but it's sad that the wall blocked 400km of views to the sea to some extend

_What Tsunami we are taking about came in 2011_ _It feels like just yesterday_ *Time flies*