At like 40% in the video i thought "why not just make a wall with a curve to throw the water back in?" And then you showed the recurve wall! But that submerged breakwater was mind blowing! I don't know if it has any environmental effect, but on the aesthetic part (+ defence ofc) its 10/10!
The submerged breakwater response is why coastal ecosystems, like coral reefs or swamps, are a great defense against inland flooding. The water breaks up on the coral or the tree roots.
yes it does have an environmental effect (if standing on the seafloor and if the size is too big) it may block the way for coral expansion and it could Close of essential hiding holes and one way entrances.
@@somedudethatripsplanetinha4221 I would imagine only if it was solid, but if it was made of soemthing like the rock armour, nly submerged, it would be great for marine life, I imagine.
I don't even know why this was a suggested video for me, I saw how long it was, and thought 'Nah I'll probably close it after 30 secs' - Here I am at the end of the 12:22 wanting more experiments. Really good video and interesting for someone who had no prior interest in this.
@@canada3186 The first ramp at the start of the video does, yes. people are like "oh that helps break the waves, maybe we can do a shorter version of that to do the same?" and then found out that the performance depends on how steep the slope is.
the ramp actually help reduce the force when water hit the wall so it wont break but ofc it will allow the water to go up (water will go down eventually ). Also the less economy while keep the beach clean and nice as you want unlike rock armour or submerged shore
Not click bait, and straight to the point, and I learned something throughout the whole video without having to wait for the very end. The rest of YT could learn a thing or two instead of wasting people's time. ;)
It's because JBA Trust isn't in YT for the money. They're in it for the PR. Actually conveying the information is more important to them than pleasing YT's fickle monetization algorithms with tons of extra watch-minutes.
I live in The Netherlands in an area that was reclaimed from the sea, we live about 4 meters below sea level. All that seperates us from a massive wall of water is this kind of technology. Very interesting to see it up close!
When I first started watching this video, I thought it would be some boring engineering jibber jabber and not cover anything, but the results actually were super interesting and I felt like I learned something new... will definitely be looking at beaches far differently now!
I've always loved engineering because of the thoughtful, interesting solutions to such big, yet also innocuous problems. Not many people will find the beauty in how the different ways a bridge is constructed, or a breakwall is designed and placed, or how air is able to be conditioned and pushed through your vents at home to keep you comfortable. The level of detail and effort we put into constructing the things we see and use everyday is quite staggering.
The part of Japan I lived in must have been a test bed for wave suppression, because you could see examples of each one of these defenses. Every few km was a different strategy. My home was about 200 meters from the "beach." As you came to it there was a ~3 meter tall wall that has a cool mural of the town's local legends. Beyond it was a wide trench, followed by another wall, beyond which were hundreds of these gigantic concrete "jacks" which acted as a rock armor. They moved a lot more though. It really felt like we were at war with the Pacific.
I saw a video on Reddit this morning of a huge pile of these giant “jacks” you’re talking about (I think called dolos) I was curious so I google dolos, then looked up how revetments work, and that’s actually how I ended up on this UA-cam video lol
I’m a landscape architecture student working on projects related to mitigating extreme storms and rising sea level. This video is extremely useful and scientific that gives us a handy support of our designs, thank you so much!!
But the submerged indentation in the offshore is expensive and the recurve wall is cheap I feel that the slope and the recurve wall is the best possible option because it's effective for it's price.
You seem to have missed the point of the video entirely. The best option is never to build the most overbuilt possible waste of taxpayer dollars, it's to build the solution that's _good enough_ to offer the needed level of protection while costing as little as possible. Some coasts, for instance parts that are already partially protected by coastal geometry, won't need anything more than a 2-foot high straight concrete wall. At another coast, the buildings might be far enough back from the water that minimal over-topping _might be acceptable,_ making a cheaper option viable. Civil engineering problems like almost never have a single best one-size-fits-all answer, every single option shown here _is_ the best option for certain situations.
Something much of the rest of the comments have been asking... (I actually do like engineering stuff but don't really go looking for it so I'm as confused as everyone else)
Why have I already clicked on this in my recommended section and then ADDITIONALLY have been watching this 4 times in a row and then immediately afterwards I had gone to school and tried to educate everybody I could find about the difference of recurved walls.
I used to do Aaaa good old days when I was a kid And used to go in the bathroom and fill up my tub and put action figures and boats and made waves and would see how the action figures and boats would react to those waves and would spent hours in the bath room The good old days :)
I would still pick the recurve wall because it preforms well, the rock armour as u said completely decimates the practicality of the beach as they had done at my beach ( hawker beach in Mt Martha ), also if u did the under water arc it would stop surf at certain beaches. Just my thought
Jamie Burnett the rock wall isn't that bad. My local beach uses it and all we have to do is just climb over a few rocks which isn't very hard to access the beach. In the past 20 years there hasn't been a serious injury related to climbing our rock wall do its actually really effective
I think that's the point, and the point of the video. Every situation is different, so the goals are different. Some beaches are nowhere near homes so there's zero chance of flooding. Some are great for surfing so you wouldn't want to obstruct the waves coming in. Some are more popular for swimming, so breaking up the waves further out is ideal. Some are popular for the beach, so you don't want to cover it up or make it inaccessible. Some are not popular at all, and so putting up a rocky barrier to protect a local community wouldn't be a problem. Watching this I was thinking a lot about California where I live. Because California has a subduction zone along the beach between the Pacific continental plate and the North American plate, most of California's coastline is cliffs and rocky. Many of the places with sandy beaches already have natural protection like cliffs, or huge beaches that extend inland. Also because California is stupid and they hate happiness they don't allow any private property on beaches, and they stuck a highway along the entire coast so there's usually like a quarter to half mile of undeveloped land across the entire coastline, making flooding virtually never occur. That's one alternative, don't let anyone live near the beach, no homes will be threatened.
I guess any site with a continuous wall defence will need some way of draining off water that overtops the wall. Or, pump it back into the sea afterwards.
That actually explains a lot! My grandparents used to have a house in a really nice neighborhood right on the ocean, but instead of having a sandy beach, there were a bunch of rocks and a concrete wall. I always wondered why, but now I know! It probably protected the houses in that neighborhood!
Make the curve top a "slide in place" system, perhaps from hard plastic. As waves erode it away, you only have to replace one section rather than the whole system.
I doubt that would work as well as you'd think - mini vortices would form next to each step and the rest of the wave above would travel over with a bit more friction.
Mr Cabot But testing scale models with everything in place at the maximum available cost is a good starting point. Put in all the features then take them away until one has a cost effective and practical model.
So rock armor with a slightly larger recurve wall and a submerged breakwater means mother nature loses the fight... or if the breakwater is to expensive make a makeshift one from rocks, rock breakers
Likewise, maybe we shouldn't be building stuff right on the riverbank and trying to keep the river funnelled into a narrow channel with vertical sides. Here's a pretty little town in France: mustseeplaces.eu/wp-content/uploads/2017/03/sainte-enimie.jpg ... and here's the same bridge from the other side at a different time of year: 1.bp.blogspot.com/-jGWm-JWReq8/TsvLb9l8llI/AAAAAAAAEh0/UHw7TlYf9bQ/s1600/ValG%2BDSC_8721.jpg We really ought to learn that rivers sometimes do that and our houses shouldn't be in the way.
See how much the water came up? Sometimes that car park gets washed. Debris, litter, dust, cars, the works, whoooosh downstream. Ste Enimie is built above the historic flood levels because they ain't thick. A lot of places are built such that the flooding doesn't quite get in, just goes over the patio: www.yorkpress.co.uk/resources/images/4463024/?type=responsive-gallery-fullscreen www.google.com/maps/@53.9568193,-1.0830768,3a,75y,326.71h,75.08t/data=!3m6!1e1!3m4!1sAF1QipOPHDNEOjG87OozzI-cW2-vZCydjMFpg00lentl!2e10!7i7200!8i3600 ... but the flooding's getting more severe and we've started building lower and lower. There's a fairly stark example an easy day's hike upstream from there on the way to Masham and Aysgarth: www.google.com/maps/@54.0956765,-1.3971217,3a,75y,292.6h,82.68t/data=!3m6!1e1!3m4!1smQK6SLX42juyFtJVehI1HA!2e0!7i13312!8i6656 Guess which buildings do and which don't get flood damage in the next 10 years. If you look to the east of there, the road down to Aldborough is the limit of how far that river's flooded in the last 25 years. You have to zoom out to see how wide it got. That means at the very least anywhere shaded blue here: flood.firetree.net/?ll=54.0570,-1.2859&zoom=12&m=13 ... shouldn't be used for new housing developments, because it *will* flood.
... except the conflict with nature itself implicit in trying to put mansions that close to the sea. Here's the "beach" at Pau do Mar, Madeira, with human for scale: i300.photobucket.com/albums/nn9/Sableagle/Madeira%202017/137%20day%203%20woman%20among%20rocks_zpscho1i5uf.jpg You can still walk on it ... sort of ... This is that same beach viewed from above: i300.photobucket.com/albums/nn9/Sableagle/Madeira%202017/153%20day%204%20Paul%20do%20Mar_zpst0igj6ue.jpg
As 17yr geology student 20+ yrs ago, I designed and ran this very experiment but with the aim of designing coastal protection in tsunami prone areas. Using a tank does help illustrate the impacts but reflected energy has to go somewhere. On the NE coast of the UK, most types of sea defence have been used and what has happened is that the reflected energy has simply made erosion worse elsewhere. From a tsunami perspective, disturbing the amplitude is the most effective method of dissipation. But the energy has to go somewhere. And it has to be far enough out to sea to avoid the wave rebuilding. I filmed at right angles, with a grid behind the tank. This allowed me to assess wave energy under the different scenarios.
One major issue that wasn’t covered is the effect of breakwaters and other coastal defences is the increased speed of beach erosion. Sea walls like demonstrated are huge contributors to exacerbated erosion of sand due to the wave energy being forced down into it (as well as up). I think this is an important topic that needs to be discussed with costal management plans.
experiments like these are very important, especially nowadays, where the volume of studies on coastal erosion leads to somewhat worrying conclusions about the advance of the sea itself. Studies like these are essential for the future of coastal defense, against these natural physical effects! Congratulations!
Just saw this on my recommended and UA-cam, in that department, more often than not, you do it so damn right. This was one of those times. Loved this video
I can attest to the rock wall. The marina I used to keep my boat at was completely man made and they used broken concrete, large rocks etc around the perimeter. At one point there was a round topped mound facing Lake Ontario with the rock wall along the base. During a really large wind storm we had waves coming from 100 miles away that were easily 15' high and while a little water came over the top to wet the grass on the lee side, that was about it. Just enough to get the grass wet so we could ski down it in our bare feet lol....You could stand at the top and see the waves crashing into the rocks and spraying every which way. We'd get a little sprinkle on us, but nothing major.
so, the best coastal defense method is 1 stepped revetments along with recurve walls, along with 2 rock armor where oystering is desired, and 3 submerged nearshore breakwater structures, where beach preservation is desired.
Zoie3x8 actually the Rocks work pretty well for Beach protection You put them a little bit out into the water like a fish pond and it's a great protected place for the keiki to swim doesn't mess with the sand or anything I like a wall would
You could just buy a long, narrow display-type fish tank, or make your own from clear acrylic or polycarbonate sheet. Acrylic, 240 x 50 x 15mm x 3: £5.22, 56 x 50 x 3mm x 2: £1.50, so it's not expensive but you need to glue it well with glue that won't dissolve or perish over time and you may need to keep it out of sunlight. You could get more sheet and cut smaller pieces to make the various walls and wedges, or buy epoxy resin and hardener and cast your own. Home brewing equipment shops sell taps for as little as £3.20. The wave generator could just be a leftover USB charger from a phone that broke, some LEGO or Meccano pieces and one more bit of plastic sheet. You can drill that stuff and put self-tapping screws into it like it's wood, so assembly isn't too hard. Make sure you position and tighten the screws in sequence from one end to the other, so there won't be any bulges putting extra stress on the walls and joints. One suggestion I'd make if you've got room is to *widen* the tank and have variable wavelengths available. Then, by shining a point light into the tank in a darkened room, you can get some really pretty shots of the waves refracting light as they themselves are refracted by the depth change where they go over cut-outs of your patreons' or Kickstarter backers' signatures, and you can send them the high-res photographs as rewards for their support.
Very Educational, and interesting. I live nowhere near a coast, but listening to this speaker explain this model clearly, I'm quite fascinated by this. Great Video. 👏👏👍👍
Everyone memeing here but honest this video is really well made. Everything was organized very well, addressing the concerns arising from the previous demonstrations step by step and the explanations were also very easily understandable. Well done!
Why would a slightly shaped short concrete wall on the shore be expensive? Every other option (except the plain wall) seemed to require like 10x as much material or installing underwater. And the plain wall should beonly marginally cheaper as it's basically the same thing.
Probably the fact that it takes up space on the beach itself, there are many touristy locations that have built in a way that placing a recurve wall would require a lot of modification to the place to stop it from being inconvenient. Take for example the Rio de Janeiro or Cancun beaches.
The extra cost isn't a matter of how much materiel is used, but more of the extra time needed to build it. They can't just pour the mix into a recurve wall mold and just let it dry. They will need to be sure that the material got into and filled the hard to reach areas.
Wow, these vidual experiments are really cool. While I was taking an Oceanography class in university, it was kinda difficult for me to imagine all those diff waves and their effects on the coast. These kind of vids are really helpful. Thanks for sharing 👏🏻👍🏻
These recurve walls are all along the Lincolnshire coast in England. The rock armour was very interesting, and in more recent years this has been used in the more 'touristy' areas of the aforementioned coast as it's more aesthetically pleasing than a very large wall. It's probably cheaper too.
Well if the rocks are already there... They're usually not, though. Rocks on a beach get eroded into sand, that's how the beach got there in the first place.
Mr BenjiBoy but as they said recurve takes away Beach functionality not to mention erosion and maintenance which I don't see happening with a pile of rocks if anything it'll become a coral reef
I enjoy this demonstration a lot!! thanks!! I live in the costa brava area in Spain and have the rock armour and the brakewater but not completely sumerged, in front of a Port in a zone with frequently winter sea storms.
Thank you for watching out video I'm glad you enjoyed it. Its great to here about real life international examples of coastal defences which we demonstrate in our wave tank!
I feel that the explanation could have been much better if they _all_ have benefits and drawbacks. By paying close attention I noticed that you said a seawall alone is just fine against small waves, so I assume the low cost is the benefit with the drawback being once it gets too large, it is terrible. But I did not hear a single downside of the recurve wall mentioned. It doesn't seem like it would be expensive, and yet all the energy from the ave is thrown back out to sea. My best guess is he just didn't test a wave higher than the recurve wall? I really would have liked to see that scenario simulated if that is the tradeoff. I was however very surprised to hear rock armor is actually cheap. I would think that, especially where the sea drops off fast, it would be very expensive.
Depends on what kind of rock armour they use - if it's just cages of oyster shells like NY, they could probably just pick up garbage from nearby restaurants at minimal cost.
Where I live has been quite interesting in this context. The community built very effective stepped revetments topped with recurved wall over 70 years ago to counter severe erosion (houses were being lost as sand dunes rapidly eroded). The defenses are still standing and form an important community asset, but the beaches stopped eroding 30 years ago and now consist of a huge gravel build up which has in some cases moved the high tide line >100m from the original defenses, the steps are now completely covered by gravel. At the same time the gravel has freshwater lakes and is developing its own ecosystem including nesting birds. The source of the gravel is an earthquake that occurred mid 1800s and caused a pulse of gravel to migrate down nearby mountains and down a large river valley to the coast many kilometres from where it has been deposited.
I guess I'm interested in coastal defence now
InstaSound Go to The Netherlands inspiration for coastal defense everywhere
I might give it a try, I'm visiting Amsterdam in September :)
You have alot of coastal defences in Zeeland, a Dutch province
InstaSound - I live at the beach, so that why the interest for me
don't we all... :-)
The recurve wall is the uno reverso card of walls.
Mother Nature: "Just throw some rocks in front of it"
And the ramp is the Draw 4
Thanks for the spoiler
Where's all the replies?
Haha yeah
News: huge tsunami is reflected with a huge uno reverse card
Japan is a great place to test these Coastal Defenses
Gets reflected to another city or counting surround the tsunami with a circle of uno reverse card what happens idk
That's gonna be news by Gen Z
Well if they actually took all this seriously them sea flooding wouldn't be a thing in india and many other countries 😂😂
Yes, I waiting for the guy drop a huge black of ice at one end of the tank and see how that little coastal wall held up.
At like 40% in the video i thought "why not just make a wall with a curve to throw the water back in?" And then you showed the recurve wall!
But that submerged breakwater was mind blowing! I don't know if it has any environmental effect, but on the aesthetic part (+ defence ofc) its 10/10!
The submerged breakwater response is why coastal ecosystems, like coral reefs or swamps, are a great defense against inland flooding. The water breaks up on the coral or the tree roots.
It might make area for coarl to grrow
Vinn Regi I'm gonna say it would be a good place for fish to build homes and other sea dwelling life
yes it does have an environmental effect (if standing on the seafloor and if the size is too big)
it may block the way for coral expansion and it could Close of essential hiding holes and one way entrances.
@@somedudethatripsplanetinha4221 I would imagine only if it was solid, but if it was made of soemthing like the rock armour, nly submerged, it would be great for marine life, I imagine.
I don't even know why this was a suggested video for me, I saw how long it was, and thought 'Nah I'll probably close it after 30 secs' - Here I am at the end of the 12:22 wanting more experiments. Really good video and interesting for someone who had no prior interest in this.
In the same position as you. For some reason, I really enjoyed it.
I know right? It was so interesting
Same here. That’s super interesting, and I’m not even living near the beach.
Excatly the same i was going to comment ^^
Parallax same hahahahah
Engineers: puts a ramp up for the water
Ramp: makes it easier for things to get up
Engineers: *:O*
I think the ramp is supposed to represent sand coming up
People behind the ramp: :0
@@canada3186 The first ramp at the start of the video does, yes. people are like "oh that helps break the waves, maybe we can do a shorter version of that to do the same?" and then found out that the performance depends on how steep the slope is.
the ramp actually help reduce the force when water hit the wall so it wont break but ofc it will allow the water to go up (water will go down eventually ). Also the less economy while keep the beach clean and nice as you want unlike rock armour or submerged shore
Not click bait, and straight to the point, and I learned something throughout the whole video without having to wait for the very end. The rest of YT could learn a thing or two instead of wasting people's time. ;)
It's because JBA Trust isn't in YT for the money. They're in it for the PR. Actually conveying the information is more important to them than pleasing YT's fickle monetization algorithms with tons of extra watch-minutes.
No jump cuts, no shaky cam, no music playing over the dialogue and no talking loud and fast. Is this UA-cam or am I dreaming.
Plus, the blue water is kinda mesmerizing.
I live in The Netherlands in an area that was reclaimed from the sea, we live about 4 meters below sea level. All that seperates us from a massive wall of water is this kind of technology.
Very interesting to see it up close!
Waar dan? Ergens bij Den Helder is de enige plek dat ik kan bedenken.
@@karelpgbr noordoostpolder denk ik
@@karelpgbr Zou ook ergens in Flevoland kunnen zijn volgens mij.
meer dan de helft van Nederland
*🎶Under the sea… under the sea!🎶*
7:05 I always wondered why the border between the sand and parking lot for Ocean Beach in San Fran had those huge concave walls. Makes sense now.
Let's just appreciate that its something educational this time that appeared in our recommendations.
One year later got recomended again :o
When I first started watching this video, I thought it would be some boring engineering jibber jabber and not cover anything, but the results actually were super interesting and I felt like I learned something new... will definitely be looking at beaches far differently now!
Kyle Li Agreed. Great video. Very informative!
ASAP1302 apparently the some 750 people who liked the comment do
I've always loved engineering because of the thoughtful, interesting solutions to such big, yet also innocuous problems. Not many people will find the beauty in how the different ways a bridge is constructed, or a breakwall is designed and placed, or how air is able to be conditioned and pushed through your vents at home to keep you comfortable. The level of detail and effort we put into constructing the things we see and use everyday is quite staggering.
Never thought I'd be watching a 12 minute video on wave defenses. Great work.
Yeah same haha
Recurved wall is a genius idea.
And yet is so simple!
@@GuilhermeMaia100 It is really elegant!
Though rock armour seems more reliable
But you cant swim back to shore if youre in the water, and boats cant bank
@@seizedsock1083 that's why they are used where NoBody is swimming like a road behind the wall, etc..
I did not expect the recurved wall to work that satisfyingly well. :o
The part of Japan I lived in must have been a test bed for wave suppression, because you could see examples of each one of these defenses. Every few km was a different strategy. My home was about 200 meters from the "beach." As you came to it there was a ~3 meter tall wall that has a cool mural of the town's local legends. Beyond it was a wide trench, followed by another wall, beyond which were hundreds of these gigantic concrete "jacks" which acted as a rock armor. They moved a lot more though. It really felt like we were at war with the Pacific.
I saw a video on Reddit this morning of a huge pile of these giant “jacks” you’re talking about (I think called dolos) I was curious so I google dolos, then looked up how revetments work, and that’s actually how I ended up on this UA-cam video lol
Yeah, In Japan they build a lot of those, lived in Yokohama for a bit.
wholesome video, wholesome comment section, this is the good part of youtube
yes, indeed, it is
Goddamn oysters! I call them rat mollusks. :) 10:07 .
Splash yeeeeee
Splash most definitely
the best video on youtube straight to the point im not an engineer but watched it to the end
The simplicity with which this guy presents each method is appreciable
Thanks To This I Somehow Understand Why There Is Randomly Rock/Wall Near Beaches
I didn't realise I was interested in this.
Me too!
same thought it was boring at first but found it pretty cool by the end haha
Agreed!
I’m a landscape architecture student working on projects related to mitigating extreme storms and rising sea level. This video is extremely useful and scientific that gives us a handy support of our designs, thank you so much!!
*UGH, not sure why this was recommended* BUT THAT WAS COOL
Safwan Hossain so tru
Ideally you'd just have the recurve wall with the offshore thing as well.
Yeah but those are both really expensive compared to the other options.
We all here are talking like we are in "Build your own City tycoon 2" :D
But the submerged indentation in the offshore is expensive and the recurve wall is cheap I feel that the slope and the recurve wall is the best possible option because it's effective for it's price.
You seem to have missed the point of the video entirely. The best option is never to build the most overbuilt possible waste of taxpayer dollars, it's to build the solution that's _good enough_ to offer the needed level of protection while costing as little as possible. Some coasts, for instance parts that are already partially protected by coastal geometry, won't need anything more than a 2-foot high straight concrete wall. At another coast, the buildings might be far enough back from the water that minimal over-topping _might be acceptable,_ making a cheaper option viable. Civil engineering problems like almost never have a single best one-size-fits-all answer, every single option shown here _is_ the best option for certain situations.
why have a recurve wall when the offshore thing prevents the beach erosion in the first place?
You came for
Wave 1: 2:04
Wave 2: 3:04
Wave 3: 4:33
Wave 4: 5:50
Wave 5: 7:22
Wave 6: 8:20
Wave 7: 9:27
Wave 8: 11:17
Pay attention at how the beach looks like.
Wave set
I came for the whole video.
Watch the whole video you'll get a better understanding
Why did I just watch this, find it mildly interesting and now find I’m somewhat knowledgeable about wave interactions with coastal structures?
Something much of the rest of the comments have been asking... (I actually do like engineering stuff but don't really go looking for it so I'm as confused as everyone else)
Why have I already clicked on this in my recommended section and then ADDITIONALLY have been watching this 4 times in a row and then immediately afterwards I had gone to school and tried to educate everybody I could find about the difference of recurved walls.
Anyone else used to make waves in the bath as a kid and put action figures and boats in it and pretend it was a tsunami
I still do it lol
I used to do
Aaaa good old days when I was a kid
And used to go in the bathroom and fill up my tub and put action figures and boats and made waves and would see how the action figures and boats would react to those waves and would spent hours in the bath room
The good old days :)
Guilty here. hehehe.
I'm glad I am not the only one
Just about everybody gamer
Who watched til the end cause its really Satisfying?
I would still pick the recurve wall because it preforms well, the rock armour as u said completely decimates the practicality of the beach as they had done at my beach ( hawker beach in Mt Martha ), also if u did the under water arc it would stop surf at certain beaches.
Just my thought
Jamie Burnett the rock wall isn't that bad. My local beach uses it and all we have to do is just climb over a few rocks which isn't very hard to access the beach. In the past 20 years there hasn't been a serious injury related to climbing our rock wall do its actually really effective
Dood Goi yea, it's not hard to climb over it's that it covers the entire beach, there is no more nice sand to walk on it's just big sharp rocks
I think that's the point, and the point of the video. Every situation is different, so the goals are different. Some beaches are nowhere near homes so there's zero chance of flooding. Some are great for surfing so you wouldn't want to obstruct the waves coming in. Some are more popular for swimming, so breaking up the waves further out is ideal. Some are popular for the beach, so you don't want to cover it up or make it inaccessible. Some are not popular at all, and so putting up a rocky barrier to protect a local community wouldn't be a problem.
Watching this I was thinking a lot about California where I live. Because California has a subduction zone along the beach between the Pacific continental plate and the North American plate, most of California's coastline is cliffs and rocky. Many of the places with sandy beaches already have natural protection like cliffs, or huge beaches that extend inland. Also because California is stupid and they hate happiness they don't allow any private property on beaches, and they stuck a highway along the entire coast so there's usually like a quarter to half mile of undeveloped land across the entire coastline, making flooding virtually never occur. That's one alternative, don't let anyone live near the beach, no homes will be threatened.
It reduces the practicality of the beach by 10%?
I've come back to watch this video like 4 times over the past few years and somehow it's still fascinating to me.
The last example together with the curved wall would be impenetrable. Cool :D
I guess any site with a continuous wall defence will need some way of draining off water that overtops the wall. Or, pump it back into the sea afterwards.
Watched this 3 times now.. don't know why but I'm really enjoying this..
want to see this : offshore wall + rock wall + recurved edge
In real operation it will be very expensive to implement , hence they dropped that combination to experiment😀
Japan 🇯🇵
The ultimate defense, also known as "the wave killer"
It would be very effective in the experiment! But for most real life implementations, overkill and expensive.
With stepped revetment
#TeamRecurveWall
#teampileofrocks
For people who want to walk down the beach not the wall
agreed #TeamRecurvedWall
_ _ mix recourved wall with rock armour
Reverse tide with #TeamRecurveWall
Real walls have curves
where can I buy the wave simulator and the wave defenses I want them
That actually explains a lot! My grandparents used to have a house in a really nice neighborhood right on the ocean, but instead of having a sandy beach, there were a bunch of rocks and a concrete wall. I always wondered why, but now I know! It probably protected the houses in that neighborhood!
seeing the waves from this perspective is very satisfying
What about a stepped revetment, but each step is recurved?
frzferdinand72 damn thats actually really smart
I would imagine smaller details like that would erode away over time
I was thinking about that also
Make the curve top a "slide in place" system, perhaps from hard plastic. As waves erode it away, you only have to replace one section rather than the whole system.
I doubt that would work as well as you'd think - mini vortices would form next to each step and the rest of the wave above would travel over with a bit more friction.
I never thought watching a video about waves would be so interesting. Now when I go to the beach I'll be checking out their design choices.
I swear the most random things can captivate a human mind. I'm hear fascinated by waves.
Try the recurved wall with sloped revetement, rock armor and submerged near-shore breakwater all together
That's far too expensive for far too little benefit. No city would ever pay for that much defence.
lich109 no, I meant to put them all together at the same time in the simulator thing
i think thats gonna be OP
Mr Cabot
But testing scale models with everything in place at the maximum available cost is a good starting point. Put in all the features then take them away until one has a cost effective and practical model.
8:47 oh, please tell me the next one is going to be a stepped recurve revetment 👀
There was a previous video from this channel which did exactly that lol
wasn't, but I hoped for it too :P
So rock armor with a slightly larger recurve wall and a submerged breakwater means mother nature loses the fight... or if the breakwater is to expensive make a makeshift one from rocks, rock breakers
yah or maybe just not build things on the beach, such as expensive and luxury apartments and hotels.
Likewise, maybe we shouldn't be building stuff right on the riverbank and trying to keep the river funnelled into a narrow channel with vertical sides.
Here's a pretty little town in France:
mustseeplaces.eu/wp-content/uploads/2017/03/sainte-enimie.jpg
... and here's the same bridge from the other side at a different time of year:
1.bp.blogspot.com/-jGWm-JWReq8/TsvLb9l8llI/AAAAAAAAEh0/UHw7TlYf9bQ/s1600/ValG%2BDSC_8721.jpg
We really ought to learn that rivers sometimes do that and our houses shouldn't be in the way.
See how much the water came up? Sometimes that car park gets washed. Debris, litter, dust, cars, the works, whoooosh downstream. Ste Enimie is built above the historic flood levels because they ain't thick. A lot of places are built such that the flooding doesn't quite get in, just goes over the patio:
www.yorkpress.co.uk/resources/images/4463024/?type=responsive-gallery-fullscreen
www.google.com/maps/@53.9568193,-1.0830768,3a,75y,326.71h,75.08t/data=!3m6!1e1!3m4!1sAF1QipOPHDNEOjG87OozzI-cW2-vZCydjMFpg00lentl!2e10!7i7200!8i3600
... but the flooding's getting more severe and we've started building lower and lower. There's a fairly stark example an easy day's hike upstream from there on the way to Masham and Aysgarth:
www.google.com/maps/@54.0956765,-1.3971217,3a,75y,292.6h,82.68t/data=!3m6!1e1!3m4!1smQK6SLX42juyFtJVehI1HA!2e0!7i13312!8i6656
Guess which buildings do and which don't get flood damage in the next 10 years.
If you look to the east of there, the road down to Aldborough is the limit of how far that river's flooded in the last 25 years. You have to zoom out to see how wide it got.
That means at the very least anywhere shaded blue here:
flood.firetree.net/?ll=54.0570,-1.2859&zoom=12&m=13
... shouldn't be used for new housing developments, because it *will* flood.
... except the conflict with nature itself implicit in trying to put mansions that close to the sea.
Here's the "beach" at Pau do Mar, Madeira, with human for scale: i300.photobucket.com/albums/nn9/Sableagle/Madeira%202017/137%20day%203%20woman%20among%20rocks_zpscho1i5uf.jpg
You can still walk on it ... sort of ...
This is that same beach viewed from above: i300.photobucket.com/albums/nn9/Sableagle/Madeira%202017/153%20day%204%20Paul%20do%20Mar_zpst0igj6ue.jpg
Until sea level goes up 10m
As 17yr geology student 20+ yrs ago, I designed and ran this very experiment but with the aim of designing coastal protection in tsunami prone areas.
Using a tank does help illustrate the impacts but reflected energy has to go somewhere. On the NE coast of the UK, most types of sea defence have been used and what has happened is that the reflected energy has simply made erosion worse elsewhere.
From a tsunami perspective, disturbing the amplitude is the most effective method of dissipation. But the energy has to go somewhere. And it has to be far enough out to sea to avoid the wave rebuilding.
I filmed at right angles, with a grid behind the tank. This allowed me to assess wave energy under the different scenarios.
Don't mind me just ruining my sleep squedule watching waves at 4 am
lads lads lads. how bout rock armor with a recurve wall. aye? aye? izipizi hire me right now.
because expensive. Rather get one good solution than two slightly better ones
RekTrain how about no beach :)
Zander Meiring
So money is more imporatant then lives?
Zander Meiring well they do combine into one good solution
RekTrain, Submerged near-shore breakwater, Rock armor + mangroves and a recurved wall.
*Just stop making waves LoL*
Jk
Near-shore breakwater + recurved wall is 100% gold.
This is actually beautiful and a very good video.
recurved wall takes away beach functionality though
Daniel Souza you forget the rocks
Breakwater is already very expensive. So either one or the other, not both :)
One major issue that wasn’t covered is the effect of breakwaters and other coastal defences is the increased speed of beach erosion. Sea walls like demonstrated are huge contributors to exacerbated erosion of sand due to the wave energy being forced down into it (as well as up). I think this is an important topic that needs to be discussed with costal management plans.
I didn't think I would watch the whole of this...
youtube recommendations you have done a good job👏👏
I was confused when this was in my recommended list. I watch it anyway and now I’m very interested. Good video
I never thought I'd be watching a 12 minute video on wave defenses.
one more video and i'll be getting my Phd in coastal defences on flood risk
I can't believe I was actually right when I thought at the beginning "Why don't we just put a 'curved' wall or something? It's the most logical thing"
experiments like these are very important, especially nowadays, where the volume of studies on coastal erosion leads to somewhat worrying conclusions about the advance of the sea itself. Studies like these are essential for the future of coastal defense, against these natural physical effects! Congratulations!
Thank you mr algorithm. This was a good watch.
This had no business being as interesting as it was, watched every second
"Stopping global warming to prevent sea level rising ... priceless." - For everything else there's coastal defenses.
Recurve wall hands down, might as well add in the rock wall, get free oyster food x)
Why do I find something like this so interesting
Best video demonstrates solves my biggest problem
I learned more in just this one video than I would in a weeks worth of goin to school
Very interesting, this is the type of daily knowledge I’m happy to learn about!
Just saw this on my recommended and UA-cam, in that department, more often than not, you do it so damn right. This was one of those times. Loved this video
want more videos like this on different natural situations in different places
So, huge failure putting in the breakwater and not a sloped beach?????
You've inspired my son's science fair project! Thanks for setting up this amazing experiment!
Brilliant...one of the most interesting, descriptive, “edutaining” videos I’ve ever watched!
What a fantastic host/educator.
why is this so cool to me, every now and then for the past 2 years I've been coming back to this video
I can attest to the rock wall. The marina I used to keep my boat at was completely man made and they used broken concrete, large rocks etc around the perimeter. At one point there was a round topped mound facing Lake Ontario with the rock wall along the base. During a really large wind storm we had waves coming from 100 miles away that were easily 15' high and while a little water came over the top to wet the grass on the lee side, that was about it. Just enough to get the grass wet so we could ski down it in our bare feet lol....You could stand at the top and see the waves crashing into the rocks and spraying every which way. We'd get a little sprinkle on us, but nothing major.
so, the best coastal defense method is 1 stepped revetments along with recurve walls, along with 2 rock armor where oystering is desired, and 3 submerged nearshore breakwater structures, where beach preservation is desired.
Zoie3x8 actually the Rocks work pretty well for Beach protection
You put them a little bit out into the water like a fish pond and it's a great protected place for the keiki to swim doesn't mess with the sand or anything I like a wall would
imagine having the job of demonstrating this with the jba trust wave tank
what a dope job that would be
the other advantage of an offshore construction (basically an artificial reef) is that it can be sculpted to make perfect, consistent waves
Dont put effort in this just call the netherlands
well just build you a dune, or a gigantic opening dam
The Dutch are masters of water management.
UA-cam recommended brought me here and I am actually impressed by this video
Nice video men, along with a decent explanation!
For someone like me that lives very near from the coastal area these things matter.
Superb demo ... truly enjoyed every second of the demo
What a great demo I’m about to go to the beach and tell these people to watch this video
I don’t know how I got here but... THIS IS AMAZING
Where do you buy this
where did you make** this
Plexi glass, servo motors and some water.
You could just buy a long, narrow display-type fish tank, or make your own from clear acrylic or polycarbonate sheet. Acrylic, 240 x 50 x 15mm x 3: £5.22, 56 x 50 x 3mm x 2: £1.50, so it's not expensive but you need to glue it well with glue that won't dissolve or perish over time and you may need to keep it out of sunlight.
You could get more sheet and cut smaller pieces to make the various walls and wedges, or buy epoxy resin and hardener and cast your own.
Home brewing equipment shops sell taps for as little as £3.20.
The wave generator could just be a leftover USB charger from a phone that broke, some LEGO or Meccano pieces and one more bit of plastic sheet.
You can drill that stuff and put self-tapping screws into it like it's wood, so assembly isn't too hard. Make sure you position and tighten the screws in sequence from one end to the other, so there won't be any bulges putting extra stress on the walls and joints.
One suggestion I'd make if you've got room is to *widen* the tank and have variable wavelengths available. Then, by shining a point light into the tank in a darkened room, you can get some really pretty shots of the waves refracting light as they themselves are refracted by the depth change where they go over cut-outs of your patreons' or Kickstarter backers' signatures, and you can send them the high-res photographs as rewards for their support.
Very Educational, and interesting. I live nowhere near a coast, but listening to this speaker explain this model clearly, I'm quite fascinated by this. Great Video. 👏👏👍👍
I can't be the only one who wants their own wave pool like this.
I've watched this video 4 times and it's still interesting
Everyone memeing here but honest this video is really well made. Everything was organized very well, addressing the concerns arising from the previous demonstrations step by step and the explanations were also very easily understandable. Well done!
What are the disadvantages of the recurve wall?
I reckon the biggest issue is that It's expensive
Why would a slightly shaped short concrete wall on the shore be expensive? Every other option (except the plain wall) seemed to require like 10x as much material or installing underwater. And the plain wall should beonly marginally cheaper as it's basically the same thing.
Probably the fact that it takes up space on the beach itself, there are many touristy locations that have built in a way that placing a recurve wall would require a lot of modification to the place to stop it from being inconvenient. Take for example the Rio de Janeiro or Cancun beaches.
it wont protect against the tide or a tsunami while the cheap rocks will but the cheap rocks take away from the beach
The extra cost isn't a matter of how much materiel is used, but more of the extra time needed to build it. They can't just pour the mix into a recurve wall mold and just let it dry. They will need to be sure that the material got into and filled the hard to reach areas.
Wow, these vidual experiments are really cool. While I was taking an Oceanography class in university, it was kinda difficult for me to imagine all those diff waves and their effects on the coast. These kind of vids are really helpful. Thanks for sharing 👏🏻👍🏻
I bet Dan from JBA wasn't expecting over 7 million views of his video!
Don't really know why this recommended but what about a zig zag wall? Seems way cheaper...
Anybody Noname There’s the aesthetic factor as well, and a zig zag wall wouldn’t help it.
Zig zag! I wonder if we can submit requests for further modeling!
Why doesn’t this channel have more subscribers? They could be our saviors!
These recurve walls are all along the Lincolnshire coast in England. The rock armour was very interesting, and in more recent years this has been used in the more 'touristy' areas of the aforementioned coast as it's more aesthetically pleasing than a very large wall. It's probably cheaper too.
UA-cam 2016: nope
UA-cam 2017: ehhh
UA-cam 2018: 1 more year
UA-cam 2019: alright guys lets learn about coastal defenses
Spirit Potato well it’s about time
Its 2020 for me
actually it has come up for about 5 years now and I watched it everytime
So rock is the best also Cheap or free
Recurved was the best
how could that possibly be free lol
Well if the rocks are already there... They're usually not, though. Rocks on a beach get eroded into sand, that's how the beach got there in the first place.
Mr BenjiBoy but as they said recurve takes away Beach functionality not to mention erosion and maintenance which I don't see happening with a pile of rocks if anything it'll become a coral reef
Salmon Ride wait I thought I did but maybe I didn't what was he saying about oysters?
I enjoy this demonstration a lot!! thanks!!
I live in the costa brava area in Spain and have the rock armour and the brakewater but not completely sumerged, in front of a Port in a zone with frequently winter sea storms.
Thank you for watching out video I'm glad you enjoyed it. Its great to here about real life international examples of coastal defences which we demonstrate in our wave tank!
Where i live it's both rock armour and the dike. So in the netherlands of courseee but it also has some systems you haven't shown here.
I feel that the explanation could have been much better if they _all_ have benefits and drawbacks. By paying close attention I noticed that you said a seawall alone is just fine against small waves, so I assume the low cost is the benefit with the drawback being once it gets too large, it is terrible. But I did not hear a single downside of the recurve wall mentioned. It doesn't seem like it would be expensive, and yet all the energy from the ave is thrown back out to sea. My best guess is he just didn't test a wave higher than the recurve wall? I really would have liked to see that scenario simulated if that is the tradeoff.
I was however very surprised to hear rock armor is actually cheap. I would think that, especially where the sea drops off fast, it would be very expensive.
It's not an explanation video its a demonstration video.
Depends on what kind of rock armour they use - if it's just cages of oyster shells like NY, they could probably just pick up garbage from nearby restaurants at minimal cost.
The model is why I love engineering but the "recurved wall" is why I love design. A subtle change to the shape of something makes a huge difference.
Where I live has been quite interesting in this context. The community built very effective stepped revetments topped with recurved wall over 70 years ago to counter severe erosion (houses were being lost as sand dunes rapidly eroded). The defenses are still standing and form an important community asset, but the beaches stopped eroding 30 years ago and now consist of a huge gravel build up which has in some cases moved the high tide line >100m from the original defenses, the steps are now completely covered by gravel. At the same time the gravel has freshwater lakes and is developing its own ecosystem including nesting birds. The source of the gravel is an earthquake that occurred mid 1800s and caused a pulse of gravel to migrate down nearby mountains and down a large river valley to the coast many kilometres from where it has been deposited.
That's so interesting, thanks for sharing!
I think a recreation of this experiment with natural barriers like mangroves could be interesting to see
We don't have 10 - 20 YEARS to wait for a mangrove tree, to mature.
I don’t really know how I ended up on this video but I’m glad I did because this was interesting as hell!!
I really wanted to see what would happen if the slope was facing the other way.
nothing really, just the water that bumps above the wall will get kinda pulled under and have a really strong undertoe