This makes me mad. Kid's gotta experiment, man. How's we supposed to learn the science stuff elsewise? >:p Feckin books? Screw books. I wanna build a thing, and watch it systemically alter itself over time based on fundamental laws!
@@Quotenwagnerianer I feel like that's a rather naieve view of science. To a certain degree it's true; you can accomplish a lot more by trusting the experts in the field to be generally correct and have a pretty good grasp on things, but science is ultimately about thinking critically and asking questions, and believing you can answer them. You build a much more intuitive understanding of a science when you're active in asking question in that field, and when you're just starting out with science, it is deeply informative and relatively straightforward to repeat experiments that have already been done, to come to your own conclusions based on those experiments, and so on. So I'm going to disagree with the sentiment you put forward. It's not a waste of time. Hell, replication studies are a huge part of scientific rigor that don't get nearly enough love; why should we discourage participation in the way you're suggesting? What does that really gain us? Fewer scientists, less question, less rigor, more biased assumptions made by a minority of people that happened to be the first to study a problem and therefore became the "experts". It is not a waste of time to study something that's already been thoroughly studied, because there is always more to learn. It is not a waste of time to tread ground that's already been tread, because until you tread that ground, you won't know what it feels like to do that, why people have made the decisions they've made. I cannot agree with the naieve assumption that science should be "left to scientists", because otherwise there will be no new scientists. That's my two cents anyway :p
@@Woodledude Half the joy in science is learning something, and later doing an experiment, any experiment, and going 'ohhh... so *thats* how that works out.'. used to spend entire days playing around in a local stream, come back muddy and sandy. but happy. would still do that if I wouldn't be looked at judgingly now I'm 20 years older XD
Rip rap may stabilize a portion of a river bank, but it creates further damage downstream. There are better and more natural ways to restore and protect a river bank, including when human infrastructure is at risk. Learn more here: www.ausableriver.org/programs/restoration
@@ausablecenter Wouldn't it be better if the riprap extended along the full length of the curve, ie from one straight to the next, rather than as placed? I understand this is for educational purposes, I'm just wondering.
This was in my recommended because I've watched one of these live, and then have watched a couple videos like this, and one of a guy just unclogging street drainage
I can imagine a bunch of people the ausable river association sitting around drinking tea and talking about rip-rafts and meanders and spring sappings.
I know you're here to help people know how to stop rivers from ruining places and stuff, but please do more videos like this. I think the entertainment value of it alone will catch people's attention which would help spread awareness much faster than most other methods. I've love to see a time lapse of how a river naturally forms from a water source. Also, making a big mountain and seeing how long it takes to erode away and collapse would be epic. uwu
@@foodforthesoul1326 Except that this is how rivers work. A sand model works the same except it speeds up the developments. Where this took a few hours a real life river will take decades/centuries
Wow, UA-cam algorithm finally recommended something good! 👍 That’s a really nice example of meandering channels and how they evolve thru time. Did my MS thesis on a very closely related subject back 20 some years ago - used ModFlow to see if drainage ditches along a road would affect cutbank erosion (inconclusive). I like how your run clearly shows the effects of riprap, and the meander cutoff was great to see, though I’m surprised you didn’t require more time.
Having already seen a similar video, I was pleasantly surprised how good this video is. I like the addition of the riprap and the detailed explanations of particular events.
I love how this exemplifies that the outside radius of a turn in most situations is where most of the energy tends to be applied to the media and where most of the wear and turbulence will occur.
Very interesting indeed. I live in a havy meander area (lower Paraná) and it could be important to talk how these kind of river usually meander inside a "flood valley". Urban development tend to ignore this area and catastrophe comes knocking at your door when the "thin" and curvy stream becomes a straight and thick river, swallowing up all the banks.
Its amazing to see it happen at both scales. I saw that effect of the river eroding and getting one turn cut, making the stream go straight. I saw it using animations and images from google maps, and it was quite impressive, but seeing it happen in real time here is so much better.
This video is very neat, I wasn't aware that the erosion of soil via groundwater was called spring sapping. Thank you for the entertainment and valuable information! :)
When using riprap it should be extended around the bends and keyed in at stable locations in the banks. I wish I had the equipment to make cool simulations like this. Excellent information. Thank you.
I’m not fully versed on this stuff but I assume riprap is rocks or other material used on the banks of streams to try and keep it in place and meander is the soil/sediment. Am I Right?
Something that blows my mind is the scale. I kayak rivers in my free time and the one by my house has bends that exceed a 1/4 mile. The amount of erosion that happens on that scale is insane
Funny how channel meander models have to start with the meanders. What will happen eventually is the formation of a braided network with multiple meander channels of varying sizes, discharges and sinuosity.
Hi Andy, Thanks for the comment. It can take a while for the meanders to develop naturally, so I think a lot of videos dig out the channel to speed up the process. In this case, I had a few hours to work with, so I formed a channel to start the model and let it run. Many factors affect the development of braided channels versus a meandering, single thread channel, including slope, sediment load, seasonal variability in discharge, etc. It can be hard to translate exactly what's happening in this model to real-life. For instance, this is an alluvial channel model with no vegetation and hard, structural controls provided by the stainless steel basin where the sediment is contained. That's not exactly a scenario found in nature. The meanders can only migrate so far before they reach the edge of the table. However, I think there is some value in seeing how a meander changes through time. Cut banks will migrate outward, chute cutoffs will occur, oxbow lakes will form, etc. It's also interesting to observe the fluid dynamics at play within the channel, and the multi-colored sediment allows for that visualization. You can see the erosion due to higher velocities on the outer edge of the channel causing cantilever failures on the cut bank, and the deposition of sediment by slower currents at the inside edge. Thanks again for engaging with us on this.
@@ausablecenter we're always making models, but sometimes, a simple one (even if oversimplified for truly practical applications to be feaseable) can give greater understanding of a subject down the line. thank you for sharing this! Would've been nice to see a reference to oxbow lakes at the very end, but given the angle you seem to have been working on (as well as the really permeable substrate) it wouldn't realy have been anything. for a teaching aid, this would be quite usefull I think. sometimes you have to learn things that are somewhat wrong, so you can later go 'ah, it's not quite right. here's how we improve it' while learning and understanding more then you did before at every step of the way.
Hmm, interesting. So, a question or so.... The wave formation of the river channel when you start is high amplitude, and short wave cycle. I remember flying into Winnipeg and seeing the river that runs through it, and it was similar to your model, except that the shape was more like that folded ribbon candy where the long sides of the wave almost touched, and the arc of the curve was very wide. I am thinking that this is a more common shape in rivers that flow through very flat land, and the more hilly the area is, the shorter the wave length is and the shorter the amplitude of the wave is. Correct, or is some thing else going on. Oh, in flat land, water flow rates would be much slower than in steeper areas, and I don't know if that would just slow the erosion process down in the flat lands but end up with a similar shape and process...
You're correct that when a river's slope is low, meanders tend to form and erode the landscape laterally. This creates wide, flat valley bottoms with the "folded ribbon candy" shape that you're describing. Over time, those long sides of the wave will narrow the meander neck, and a cutoff will form, like the one in the video. Steeper channels have very low sinuosity and erode their landscapes vertically, creating deep, narrow V-shaped valleys.
The section cut off becomes a billabong, or oxbow lake. The billabong might dry out over time, or become filled when the river floods its banks and overflows back into it.
This is a bit off topic but I believe that remnants of meander cutoffs have been observed on Mars which is another big reason to believe that water once flowed throughout the planet.
So thought experiment question; if given enough time and assuming all factors controlled (human activity, plate tectonics long term, etc) would all rivers eventually strive to be as straight as possible? It reminds me of the coffee creamer and entropy comparison.
Not quite. Check out our blog to learn more: www.ausableriver.org/blog/why-do-streams-meander#:~:text=Meanders%20are%20produced%20when%20water,pool%20structure%20of%20a%20stream.
I do have a few questions: I know it would mostly depend on the local area but how long would this particular outcome take on average? Would adding more ripraps increase erosion speed downstream?
I have a river near my house and I have seen a lot of these formations in it. It's not nearly as bendy but now I know how in some parts there are just these ledges and in others, "beaches" were created.
This was super helpful in helping me understand for a uni assignment! If the model was deeper with more sand under the rip rap, would it eventually undercut the rip rap & cause it to collapse?
Great question! I have bachelor's and master's degrees in geology and have been a licensed professional geoscientist for 15 years. Unfortunately, even I don't get to play with the table all day, every day :-( If you'd like to make a career out of playing with these kinds of toys, I might suggest becoming a professor of geomorphology at a university. Good luck!
There are methods to help combat erosion induced structural collapse of housing and other buildings along river banks, but ultimately the water consumes all. It’s best to build a safe distance away from the water’s edge. That said, if you do build too close to the banks, and you _really_ want the building to last centuries down the line when the erosion eventually will be an issue to the foundations, place it on piles going into bedrock, and elevate the building well above the flood line.
That largely depends on the type of tree and geomorphological nature of the river. Trees are a critical component for bank stabilization, but major flood events can still have an adverse impact on erosion, and some trees (such as white pines) provide limited root structure to hold soil in place compared to other species (like silky dogwood, who's roots can extend 12 or more feet into the soil).
@@Kyle-xk2rb I just worked out an approach which I guess could work. Would you like to see the algorithm? If it eventually works, it's possible to finish developing the mod.
Natural stream restoration methods is the better solution. This is a complicated process outside the scope of a UA-cam comment. You can learn more about natural stream restoration on our website: www.ausableriver.org/programs/restoration/natural-stream-restoration
I can remember being told 40 to 50 years ago that the more the river meanders the less the fall in the land. Greater fall leads to straighter river and more current. Is this still correct? I think this info came from The US Army of engineers and the attempts to straighten the Mississippi River. The straight river was trying to meander again
Is there much difference if you vary the stream flow periodically over time ? IRL there would be annual spring runoffs followed by summer dries and then back again, would this lead to a significant difference in the outcome ?
This would lead to a variable outcome, however this simulation is designed to speed up the meander/erosion process, and the results you see would take place over a long period of time (see answers to similar questions below). The amount of time this process takes will take into account the variability of stream flow over time.
I don't know if it's considered rip rap, but I've seen rivers and creeks in Oklahoma where farmers had placed old cars, tires, and other junk into the banks to prevent erosion (mostly so they didn't lose land for farming etc.) Kind of interesting when you run across those things.
This is a very interesting subject I didn't realize I wanted to watch, but even the time lapse portions of the video are out of focus, let alone the rest of it. The bitrate of youtube already makes it difficult to make out what's going on with all the moving sand
That's a great question. (that's a stalling tactic I used as a teacher when I didn't know the answer ;-) It's a little difficult to say what the timescale would be. In a natural system, there would be vegetation to counter the erosion of the streambanks. This model isn't constrained by the presence of vegetation. Also, the size of the meanders in real life is going to make this a much slower process. It would probably take several decades (maybe the better part of a century?) for a meander of these proportions on a large river to narrow at the neck and eventually cut off. Climate, vegetation, and geology would also factor into that process. Thanks for the question!
Super interesting, great video! Somehow I think it's noticeable that the starting state of the model is artificial, i.e artificially narrow river and so on. But we have to start somewhere.
Not a weird question at all. This is from the website of the company that makes these tables: "The media is made of recycled, ground melamine plastic and is about 60 percent the density of quartz sand (1.6 g/cc). This means the media can demonstrate river behavior and channel morphology with impressive accuracy at the space and time scales of our river models."
For the non-Earth Science peeps in the comments, basically the turning points of the water are cutbanks and are banks that are cut(no way lol). This is because erosion is higher here since water wants to continue to move straight(inertia) so most of the force is forward on these cutbanks.
No comment on how the river was cutting into the bank before the riprap, and how you had to fix it at one point because it had cut *behind* the riprap?
I didn't interfere with the banks during the simulation. I believe that I did point out how the eddies were scouring the bank immediately upstream of the riprap. If the simulation had continued, the scouring would have likely flanked the riprap and caused the bank to fail. Thanks for engaging on this topic with us.
It will continue to extend the reach of the program. Riprap causes energy and erosion issues up and downstream from the site. You can learn more about good alternatives on our website: www.ausableriver.org/programs/restoration/natural-stream-restoration
What happens if you keep the simulation running? Of course you have to put the washed away sand back to the start, but aside from that, you can keep this running forever and it will eventually keep forming new meanders, right?
Rivers will naturally continue to meander. You can learn more about this process via our blog: www.ausableriver.org/blog/why-do-streams-meander#:~:text=Meanders%20are%20produced%20when%20water,pool%20structure%20of%20a%20stream.
I have no idea what half these words mean but I just think it’s neat
Haha you can check out some of the words here: www.ausableriver.org/programs/glossary
@@ausablecenter thank you :D
@Boco Corwin I think the word he may have used was riffraff.
Thank God for riprap
And when me and my friends did this in the back yard when I was ten my parents called it "making a mess" and sent me to my room.
This makes me mad. Kid's gotta experiment, man. How's we supposed to learn the science stuff elsewise? >:p Feckin books? Screw books. I wanna build a thing, and watch it systemically alter itself over time based on fundamental laws!
@@Woodledude But that is just a waste of time if someone else has already done it and wrote their observations into a book. :P
@@Quotenwagnerianer I feel like that's a rather naieve view of science. To a certain degree it's true; you can accomplish a lot more by trusting the experts in the field to be generally correct and have a pretty good grasp on things, but science is ultimately about thinking critically and asking questions, and believing you can answer them.
You build a much more intuitive understanding of a science when you're active in asking question in that field, and when you're just starting out with science, it is deeply informative and relatively straightforward to repeat experiments that have already been done, to come to your own conclusions based on those experiments, and so on.
So I'm going to disagree with the sentiment you put forward. It's not a waste of time. Hell, replication studies are a huge part of scientific rigor that don't get nearly enough love; why should we discourage participation in the way you're suggesting? What does that really gain us? Fewer scientists, less question, less rigor, more biased assumptions made by a minority of people that happened to be the first to study a problem and therefore became the "experts".
It is not a waste of time to study something that's already been thoroughly studied, because there is always more to learn. It is not a waste of time to tread ground that's already been tread, because until you tread that ground, you won't know what it feels like to do that, why people have made the decisions they've made.
I cannot agree with the naieve assumption that science should be "left to scientists", because otherwise there will be no new scientists.
That's my two cents anyway :p
@@Woodledude Half the joy in science is learning something, and later doing an experiment, any experiment, and going 'ohhh... so *thats* how that works out.'. used to spend entire days playing around in a local stream, come back muddy and sandy. but happy. would still do that if I wouldn't be looked at judgingly now I'm 20 years older XD
@gyrergd That makes me thing and imagine parents as a river, wonder where the rip rap is?....
That rip rap really comin in clutch, huh
Rip rap may stabilize a portion of a river bank, but it creates further damage downstream. There are better and more natural ways to restore and protect a river bank, including when human infrastructure is at risk. Learn more here: www.ausableriver.org/programs/restoration
@@ausablecentermakes sense... thanks
@@ausablecenter Wouldn't it be better if the riprap extended along the full length of the curve, ie from one straight to the next, rather than as placed? I understand this is for educational purposes, I'm just wondering.
@@nicotti Imagine a real river, stretching for miles
@@nicotti For a portion of it. But I think the bend after the riprap ends would be hit fairly hard and erode much faster
me watching the entire time: Come on meandering stream, daddy wants to see an oxbow lake
I'm playing Minecraft and this is what pops up in recommended...needless to say I'm intrigued
Recommended videos are the best!
@@ausablecenter and after, I continued to watch more videos of these simulations
@@ausablecenter this is oddly soothing
This was in my recommended because I've watched one of these live, and then have watched a couple videos like this, and one of a guy just unclogging street drainage
word
I can imagine a bunch of people the ausable river association sitting around drinking tea and talking about rip-rafts and meanders and spring sappings.
You forgot about the eddies
@@yadai4188 - I bet they're making fun of people called Eddie.
I know you're here to help people know how to stop rivers from ruining places and stuff, but please do more videos like this.
I think the entertainment value of it alone will catch people's attention which would help spread awareness much faster than most other methods.
I've love to see a time lapse of how a river naturally forms from a water source.
Also, making a big mountain and seeing how long it takes to erode away and collapse would be epic. uwu
Why does it need to have an UwU at the end
@@w_ldan What _doesn't_ need an UwU at the end?
@@bernadettavarley exactly uwu
@@cancercentral9997 yes uwu
lmfao- uwu
"Riprap is keeping the meander from migrating" sounds like a plumbus commercial
Riprap: "We ask for nothing, Master. "
Meanderfurter: "And you shall receive it. In abundance!"
LOL, the R&M army is everywhere.
hahahaha! nice
So does "Eddies form upstream of the riprap"
The fascinating part was that the bulk of the cut-through was done on the downstream side of the isthmus. Did not see that coming.
it is 2 am, what am I doing here instead of sleeping ?
Why is this so strangely interesting? I’m gonna go watch more videos of how rivers work.
This is not how rivers work. This is how a sand model of a river works.
@@foodforthesoul1326 Except that this is how rivers work. A sand model works the same except it speeds up the developments. Where this took a few hours a real life river will take decades/centuries
I never really knew much about this kinda stuff but watching these videos has taught me more than school ever did
Of all the videos on youtube I chose this one to watch while I eat my meal. It was a good decision.
Wow, UA-cam algorithm finally recommended something good! 👍 That’s a really nice example of meandering channels and how they evolve thru time. Did my MS thesis on a very closely related subject back 20 some years ago - used ModFlow to see if drainage ditches along a road would affect cutbank erosion (inconclusive). I like how your run clearly shows the effects of riprap, and the meander cutoff was great to see, though I’m surprised you didn’t require more time.
Having already seen a similar video, I was pleasantly surprised how good this video is. I like the addition of the riprap and the detailed explanations of particular events.
I'm currently designing the map of a comic whose story I'm creating, these types of videos always help to give tales a bit more realism.
As a DM I agree...
I love how this exemplifies that the outside radius of a turn in most situations is where most of the energy tends to be applied to the media and where most of the wear and turbulence will occur.
Yes, it's a nice visual.
Very interesting indeed. I live in a havy meander area (lower Paraná) and it could be important to talk how these kind of river usually meander inside a "flood valley". Urban development tend to ignore this area and catastrophe comes knocking at your door when the "thin" and curvy stream becomes a straight and thick river, swallowing up all the banks.
Its amazing to see it happen at both scales. I saw that effect of the river eroding and getting one turn cut, making the stream go straight. I saw it using animations and images from google maps, and it was quite impressive, but seeing it happen in real time here is so much better.
No idea why videos like these are coming up in my recommended but dang do I enjoy them
damn youtube algorithm be recommending me how rivers work, thank you
Spring sapping... I just learned a new term. I loved "playing" with the stream table in high school.
This guy is very underrated
This video is very neat, I wasn't aware that the erosion of soil via groundwater was called spring sapping. Thank you for the entertainment and valuable information! :)
Im wondering if its a term just used in relation to river meanderings or ground water in general
I love this kinda stuff
When using riprap it should be extended around the bends and keyed in at stable locations in the banks. I wish I had the equipment to make cool simulations like this. Excellent information. Thank you.
UA-cam:
Videos from channels I have been subbed to for years: Nope
Random video about topic I have never searched: Here you go
From a suppposed "scientist". LMFAO!
I’m not fully versed on this stuff but I assume riprap is rocks or other material used on the banks of streams to try and keep it in place and meander is the soil/sediment. Am I Right?
Yes, riprap would be the large rocks placed along the meander to slow the migration of the meander. However, it is not a permanent solution.
It's really cool to see a simulation of how rivers meander in real time
Oxbow lakes are formed when the river's meander is too wibbly wibbly wobbly to maintain the course it's on.
This is the comment I was searching for.
You know what youtube, this IS interesting to me and I WILL watch it, thank you!
I'd love to have a table like this that I could just place a glass top on and watch how a model river evolves.
I learnt about them in middle school geography class - really cool to see these things in action
I could watch these all day long
You just might want to do that.
This is fire bro keep posting
Excellently presented and very, very educational! Thanks for sharing!!
I should be asleep buuuuut when a recommendated video like this comes up, it catches my attention
Something that blows my mind is the scale. I kayak rivers in my free time and the one by my house has bends that exceed a 1/4 mile. The amount of erosion that happens on that scale is insane
Brings back memories of university... My lecturer had a bit of a speech impediment, so it was whrip whap in our class...
Mark my words, this is going viral
Funny how channel meander models have to start with the meanders.
What will happen eventually is the formation of a braided network with multiple meander channels of varying sizes, discharges and sinuosity.
Hi Andy,
Thanks for the comment. It can take a while for the meanders to develop naturally, so I think a lot of videos dig out the channel to speed up the process. In this case, I had a few hours to work with, so I formed a channel to start the model and let it run. Many factors affect the development of braided channels versus a meandering, single thread channel, including slope, sediment load, seasonal variability in discharge, etc.
It can be hard to translate exactly what's happening in this model to real-life. For instance, this is an alluvial channel model with no vegetation and hard, structural controls provided by the stainless steel basin where the sediment is contained. That's not exactly a scenario found in nature. The meanders can only migrate so far before they reach the edge of the table. However, I think there is some value in seeing how a meander changes through time. Cut banks will migrate outward, chute cutoffs will occur, oxbow lakes will form, etc. It's also interesting to observe the fluid dynamics at play within the channel, and the multi-colored sediment allows for that visualization. You can see the erosion due to higher velocities on the outer edge of the channel causing cantilever failures on the cut bank, and the deposition of sediment by slower currents at the inside edge. Thanks again for engaging with us on this.
@@ausablecenter we're always making models, but sometimes, a simple one (even if oversimplified for truly practical applications to be feaseable) can give greater understanding of a subject down the line. thank you for sharing this!
Would've been nice to see a reference to oxbow lakes at the very end, but given the angle you seem to have been working on (as well as the really permeable substrate) it wouldn't realy have been anything.
for a teaching aid, this would be quite usefull I think. sometimes you have to learn things that are somewhat wrong, so you can later go 'ah, it's not quite right. here's how we improve it' while learning and understanding more then you did before at every step of the way.
Ah man, if only the bypass happened sooner, the bottom house would have been spared...
This is like an episode of interdimensional cable
Nature's pretty neat.
@@ausablecenter i really hope you understood the reference lol
@@DatDuckOfficial Haha we understood it a "little bits." ;-)
Hmm, interesting. So, a question or so.... The wave formation of the river channel when you start is high amplitude, and short wave cycle. I remember flying into Winnipeg and seeing the river that runs through it, and it was similar to your model, except that the shape was more like that folded ribbon candy where the long sides of the wave almost touched, and the arc of the curve was very wide. I am thinking that this is a more common shape in rivers that flow through very flat land, and the more hilly the area is, the shorter the wave length is and the shorter the amplitude of the wave is. Correct, or is some thing else going on. Oh, in flat land, water flow rates would be much slower than in steeper areas, and I don't know if that would just slow the erosion process down in the flat lands but end up with a similar shape and process...
You're correct that when a river's slope is low, meanders tend to form and erode the landscape laterally. This creates wide, flat valley bottoms with the "folded ribbon candy" shape that you're describing. Over time, those long sides of the wave will narrow the meander neck, and a cutoff will form, like the one in the video. Steeper channels have very low sinuosity and erode their landscapes vertically, creating deep, narrow V-shaped valleys.
This is some pretty good meander evolution simulation ASMR.
how was this erosion table built, and are there directions available? and how did you keep sand from piling up at the bottom of the table?
It's an Emriver table, they have an extensive website for their products!
things like this intrigue me so much and I have no clue why
This is super cool. Can you do more videos like this? I love watching the way the river evolves!
Then watch a real river. This is bogus.
Cleared all the concepts. Beautiful.
I have a question will the forgotten u shape transform back into a normal land or it will stay useless lake like in the video
The section cut off becomes a billabong, or oxbow lake. The billabong might dry out over time, or become filled when the river floods its banks and overflows back into it.
This is a bit off topic but I believe that remnants of meander cutoffs have been observed on Mars which is another big reason to believe that water once flowed throughout the planet.
So thought experiment question; if given enough time and assuming all factors controlled (human activity, plate tectonics long term, etc) would all rivers eventually strive to be as straight as possible? It reminds me of the coffee creamer and entropy comparison.
Not quite. Check out our blog to learn more: www.ausableriver.org/blog/why-do-streams-meander#:~:text=Meanders%20are%20produced%20when%20water,pool%20structure%20of%20a%20stream.
Is there a reason why the bank opposite to the bank fortified with rip rap wasn't being eroded?
The momentum of the water as it rounds the curve pushes it into the rocks. There is much less pressure applied to the opposite side.
@@MoneyManHolmes I believe the fact that the water at the inside of the curve also makes it less damaging
Helped a lot to understand the consept.Thank you very much for the nice demonstration
*in a monotone voice* "the house has collapsed into the river." Imagine all news anchors were like this
I do have a few questions: I know it would mostly depend on the local area but how long would this particular outcome take on average? Would adding more ripraps increase erosion speed downstream?
You can see detailed answers to this first question in comments below. Yes, adding more riprap would increase erosion speed downstream.
it's too short! I want to see what will happen next
Maybe we'll make another video!
are you sure the sand scale is realistic for this kind of experiences?
I love these kind of videos!
I have a river near my house and I have seen a lot of these formations in it. It's not nearly as bendy but now I know how in some parts there are just these ledges and in others, "beaches" were created.
This was super helpful in helping me understand for a uni assignment! If the model was deeper with more sand under the rip rap, would it eventually undercut the rip rap & cause it to collapse?
Excellent video, would love to see more of the stream table
what degree do I gotta get to be able to play with a sand table all day like that
Guess you have to get a master's degree or an engineering one in hydrodynamics to do this
Great question! I have bachelor's and master's degrees in geology and have been a licensed professional geoscientist for 15 years. Unfortunately, even I don't get to play with the table all day, every day :-( If you'd like to make a career out of playing with these kinds of toys, I might suggest becoming a professor of geomorphology at a university. Good luck!
We are playing things like this with my kids every spring! ;)
Most rivers here in the Netherlands have Groyne so the river won't change near populated area's
Oxbow lake formed at the end of the video
There are methods to help combat erosion induced structural collapse of housing and other buildings along river banks, but ultimately the water consumes all. It’s best to build a safe distance away from the water’s edge. That said, if you do build too close to the banks, and you _really_ want the building to last centuries down the line when the erosion eventually will be an issue to the foundations, place it on piles going into bedrock, and elevate the building well above the flood line.
wasn’t looking for this but it was fun to see
Interesting, I've been getting your videos lately and I'm really liking it, thank you.
"Riprap was placed on the cut of this meander bend"
Me, an intellectual: "Ah yes, of course."
Shoutout to the first aid kit.
What about the lack of tree roots in this simulation? They are a major factor in controlling erosion.
That largely depends on the type of tree and geomorphological nature of the river. Trees are a critical component for bank stabilization, but major flood events can still have an adverse impact on erosion, and some trees (such as white pines) provide limited root structure to hold soil in place compared to other species (like silky dogwood, who's roots can extend 12 or more feet into the soil).
I planned to make a mod which would change the water from static to dynamic in Factorio. But I stopped halfway.
Ayyy factorio i love that game
@@Kyle-xk2rb I just worked out an approach which I guess could work. Would you like to see the algorithm? If it eventually works, it's possible to finish developing the mod.
@@Kyle-xk2rb mods.factorio.com/mod/DynamicWater
me :Watching
The guy:The house has fallen into the river
in lego city
So then if the riprap furthers weathering downstream, what is the better solution?
Natural stream restoration methods is the better solution. This is a complicated process outside the scope of a UA-cam comment. You can learn more about natural stream restoration on our website: www.ausableriver.org/programs/restoration/natural-stream-restoration
I can remember being told 40 to 50 years ago that the more the river meanders the less the fall in the land. Greater fall leads to straighter river and more current. Is this still correct?
I think this info came from The US Army of engineers and the attempts to straighten the Mississippi River. The straight river was trying to meander again
Thanks for the suggestion UA-cam. I'm not exactly sure why, but whatever I guess
Is there much difference if you vary the stream flow periodically over time ? IRL there would be annual spring runoffs followed by summer dries and then back again, would this lead to a significant difference in the outcome ?
This would lead to a variable outcome, however this simulation is designed to speed up the meander/erosion process, and the results you see would take place over a long period of time (see answers to similar questions below). The amount of time this process takes will take into account the variability of stream flow over time.
I don't know if it's considered rip rap, but I've seen rivers and creeks in Oklahoma where farmers had placed old cars, tires, and other junk into the banks to prevent erosion (mostly so they didn't lose land for farming etc.) Kind of interesting when you run across those things.
This is a very interesting subject I didn't realize I wanted to watch, but even the time lapse portions of the video are out of focus, let alone the rest of it. The bitrate of youtube already makes it difficult to make out what's going on with all the moving sand
What is the timescale?
1second = how many days / months?
That's a great question. (that's a stalling tactic I used as a teacher when I didn't know the answer ;-)
It's a little difficult to say what the timescale would be. In a natural system, there would be vegetation to counter the erosion of the streambanks. This model isn't constrained by the presence of vegetation. Also, the size of the meanders in real life is going to make this a much slower process. It would probably take several decades (maybe the better part of a century?) for a meander of these proportions on a large river to narrow at the neck and eventually cut off. Climate, vegetation, and geology would also factor into that process. Thanks for the question!
I saw a video of an amazonian river, it took like 20 years in this particular case: ua-cam.com/video/nGJXxAZPm8M/v-deo.html
Super interesting, great video!
Somehow I think it's noticeable that the starting state of the model is artificial, i.e artificially narrow river and so on. But we have to start somewhere.
I know this is a weird question... but what type and/or brand of sand is that?
Not a weird question at all. This is from the website of the company that makes these tables:
"The media is made of recycled, ground melamine plastic and is about 60 percent the density of quartz sand (1.6 g/cc). This means the media can demonstrate river behavior and channel morphology with impressive accuracy at the space and time scales of our river models."
There was the 50 minute stream ecology lecture on rifles pool run sequences distilled into five minutes
For the non-Earth Science peeps in the comments, basically the turning points of the water are cutbanks and are banks that are cut(no way lol). This is because erosion is higher here since water wants to continue to move straight(inertia) so most of the force is forward on these cutbanks.
Can you make a educational video about man made ponds?
Perhaps eventually. We're very busy, though, so it could take a while.
No comment on how the river was cutting into the bank before the riprap, and how you had to fix it at one point because it had cut *behind* the riprap?
I didn't interfere with the banks during the simulation. I believe that I did point out how the eddies were scouring the bank immediately upstream of the riprap. If the simulation had continued, the scouring would have likely flanked the riprap and caused the bank to fail. Thanks for engaging on this topic with us.
Have you ever tried recreating the Northwestern floods that created the eastern Washington Scablands?
We have not at this point.
Man gets to play in a sandbox all day
Imagine playing a survival game, building your house on a riverside because it looks nice, then finding it one day just in the water
And the bypass’d meander becomes an Ox-Bow lake.
4:47
OXBOW LAKES ARE FORMED WHEN A RIVERS MEANDER-
So what happens if you place a riprap at the place where the first riprap causes the extra erosion?
It will continue to extend the reach of the program. Riprap causes energy and erosion issues up and downstream from the site. You can learn more about good alternatives on our website: www.ausableriver.org/programs/restoration/natural-stream-restoration
idk why but this is so cool
What happens if you keep the simulation running? Of course you have to put the washed away sand back to the start, but aside from that, you can keep this running forever and it will eventually keep forming new meanders, right?
Rivers will naturally continue to meander. You can learn more about this process via our blog: www.ausableriver.org/blog/why-do-streams-meander#:~:text=Meanders%20are%20produced%20when%20water,pool%20structure%20of%20a%20stream.
This is entertaining and informative.
Very nice illustration.
An Oxbow Lake I believe or as We in Australia know them a Billabong.
Fun word!
i feel like i could watch this for hours
And so the ox bow was formed
where those houses insured?
Flood insurance is not part of the standard homeowners policy. Wonder about bank erosion over time insurance?