How To River

[@profwaldone]

In my world I have a river that disappears down into a cave system but, every year this large ice dam upstream melts and breaks, flooding the whole valley. so sometimes this forest seems like it has no flowing water in it. except for a few days a year where the entire forest is flooded. as a result of this, the village that inhabits this forest is built high off the ground. and has a festival during the flood.

[@mgk3176]

Sounds cool^^

[@pierreproudhon9008]

I feel like he should probably talk about how ice dams are gona have an effect, it’s such an inspiration but a lot of people don’t know it exists. In China a section of the yellow river freezes over every winter, flooding the upstream while drying the downstream, truly peculiar indeed.

[@skyworm8006]

bro isn't this the plot of ice age 2

[@Hallow1]

@@skyworm8006 oml

[@SBVCP]

@@pierreproudhon9008 indeed

[@allanjohnson8951]

An important note on deltas: The river's speed will determine how much sediment is deposited. The slower the river, the more sediment will be deposited. Deltas form because on meeting the larger body of water, its speed abruptly slows, and sediment is deposited where the stream slows. So, sediment is deposited at the existing coastline, and the coastline moves out as more sediment is deposited, etc. etc. until you have a fan-shaped protrusion into the body of water. As such, you will almost never see a straight coastline where the delta forms.

[@enoshade]

@ThfKiller I believe that this may have something to do with the fact that much of the Netherlands' coastlines are made up of reclaimed land, i.e, the land used to be submerged in the sea. Since the coastlines have been moved outwards, the river would already have had a delta formed further upstream.

[@StarlitSeafoam]

"the evolving paths of a river can lead to interesting territory disputes" Thank you, Artifaxian, for that shot of inspiration! What a fantastic source of friction for the clans in my city state.

[@trevorvanderwoerd8915]

I think it is worth pointing out that these sorts of border disputes probably would not occur much (if at all) before the use of GPS and computers to mark where the boundary "should be." Rivers were used as borders because they are hard to cross. Since their flow path changes slowly, the people tend to just move with it since they still can't cross easily.

[@lordbeetrot]

@@trevorvanderwoerd8915true

[@lukecampbell6647]

When drawing rivers on made-up maps, it is useful to remember that they flow perpendicular to elevation contours. Don't have them cutting across your contour lines at weird angles!

[@vaultdude4871]

So they dont cut straight to elevation levels?At least not always?

[@lukecampbell6647]

@@vaultdude4871 The direction straight downhill is always directly perpendicular to elevation lines - the river flowing downhill will always make a right angle to the elevation contours.

[@jasonreed7522]

Also streams will make little v or u shaped dents in your elevation contour lines pointed up stream/hill. Basically the stream eroded out a valley and this means that the elevation line gets bent in the uphill direction. Also he forgot that a river with little sediment (say draining a lake or rocky bottom/shallow bedrock) can create an inward dent typically creating an estuary. (St. Lawrence River in Canada for an example as obvious as the Nile or Mississippi on a map)

[@ValkyRiver]

What about a civilization that creates its own rivers?

[@frafraplanner9277]

@@ValkyRiver Canals?

[@jantala3243]

look im drawring a map and i stop to look on youtube and BAM artifexican

[@kyled2153]

lol nice

[@flamingmonkey01]

Literally the reason I'm here. Went to resume work on my world map, decided to look up how winds effects climate and down the rabbit hole of this guys channel I went

[@ZackLitchfield]

Awesome to see a shoutout for the Santa Fe River! I grew up right near by and have been to O'Leno quite a few times. Always thought it was a really cool aspect of our local geography!

[@theintrovertedarcanist984]

There’s a magical river in my setting that has superfluidity- if you drop a rock in it, the ripples will bounce back and forth indefinitely. And it flows uphill in some parts.

[@KaitlynFedrick]

Alternative title: Namai.

[@Crosshill]

you cant imagine how much glee the phrase "riverine exotica" brought me, i need more river content in my life to make up for how little information there is online about dujiangyan

[@boudicathebrave]

You have no idea how excited I am to see you talk about meander geometry! I did my senior project in college on meander geometry. An interesting thing about the radius of curvature to channel width ratio being the same in rivers is that it doesn't matter what material/setting the river is in --- it holds true for rivers in tropical locations, temperate, bedrock, permafrost, and even straight ice (though the bedrock and ice ones have more variance than the others). This is due to fluid dynamics being the primary driver of that meander (which we still don't fully have figured out). The initial study done on this was in the 60s but since it was all done by physical river survey, it was heavily biased towards temperate European and US rivers. I used satellite images to measure meanders in different settings around the world and confirmed that the original findings were still sound.

[@JohnBender1313]

The Santa Fe river also has a massive cave/spring system and best campgrounds anywhere, Ginnie Springs.

[@scptime1188]

I NEEDED THIS. You always deliver on time. First with the ore video and now this!

[@liammiller6247]

I never knew I wanted to know how to river! Awesome work!!!

[@martinb.3997]

I feel like these are more educational videos than anything else, because holy ---- the detail in explanations is insane

[@dreamenvoy1530]

I was waiting a long time for you to upload such a video. I've been having a lot of trouble putting rivers on my map because the only knowledge I was going by was rivers flowing down areas of higher elevation to lower elevation, and that they never split apart. No indication of what side of a mountain the river should flow down, no indication of how wide or what shape the rivers should be, etc until now. Thank you so much ^^

[@scriptea]

Holy crap. That formula is a godsend. I've been trying to find something like that for *years*. Thank you so much.

[@frogman1]

dude, ive never seen content like this on youtube before. fantastic work!

[@The_Jovian]

Don't know how I got here or why KZbin thought I needed this video but I was entertained 👍

[@lukebortot7625]

I have seen in several of your videos that river never split. This is a good general rule, but is not always true. In fact its a common enough phenomenon that it has a name: a distributary. Perhaps the most well known distributary from the real world is the Atchafalaya river. About 160 miles from the coast (well before the river delta) the Mississippi river diverges into 2 separate streams: the Mississippi that leads to New Orleans and the Atchafalaya that leads to Morgan City. Distributaries are not a super common occurrence but there are a few dozen of them in the real world. However, because it is usually an unstable configuration they usually do not last very long. A river will bifurcate for any number of reasons for a a few years or decades before one of the streams will become dominant causing the other to dry up.

[@scary.garcia]

Did not expect to see the Santa Fe River on an Artifexian video. It’s not far from my home 😲

[@semurobo]

Am I the only one who watches this Channel who is Not interested in building a world myself, but simply in the knowledge He Provides about our universe?

[@markholloway6079]

That certainly was another highly informative video from I have been looking into that very subject recently..U R Da Man !

[@Erik_Hecker]

Never been so early

[@kemae]

Same

[@carpo719]

There's a first time for everything

[@jordanberndt4157]

In rare instances, two rivers can flow out of a lake, it's called a bifurcation lake, but the topographical circumstances for their creation are unusual. It wouldn't be unrealistic to include one in your world, but make sure use them very sparingly and rarely.

[@av3stube480]

If this was how geography was taught at my school it'd be my favourite subject.

[@onlyMetalisMusic]

Awesome video again! Could you do one about mountainous climate? And maybe one on swamps/marshes/etc.? Thank you for you fantastic work!

[@masongoser5627]

How DARE you get me into another topic? Now I'll have no free time! Excellent video, count me among your subscribers

[@SC-zq6cu]

Can't wait for him to draw rivers in artifexia

[@JustNierninwa]

8:25 applying this to the rive where I'm from predicts a 50 m wide (if by meander length) or 30 m wide (if by radius), but the river is at best 7 or 8 meters - and that's when it's full! Being a Mediterranean climate means in summer it shrinks to a measly stream of water (or sometimes dries out completely - added bonus, karst ground) and sure, it probably used to be bigger as it's said that in Roman times there were boats on it and if you take the entire surrounding area that looks like a river bed you can stretch it to maybe 20 to 25m wide, but it hasn't been that full in 1000 to 2000 years, since humans started to mess with the water upstream. So really, my question is: how long does it take to adapt?

[@bluestickman2684]

Never clicked so fast

[@Cinderbloom]

One thing I kinda felt was missing was how rivers form in lowland regions exclusively. Places like Denmark still have rivers, though not very big ones.

[@kherstein9581]

Can you please do a video on mountains, about how they are, climate and all the stuff?

[@ArkinMC]

What I really love about your videos, except from the world building aspect: I get a free, short repetition of my previous semesters in geology 😁

[@SouthernCyclops]

I would love to see a video from you about an inverted earth where the land masses and water are swapped.

[@Thecrownswill]

About time.

[@FakeDelTaco]

what if the seawater the river empties out into is really deep, so that all the sand that would go into forming a delta instead goes into water so deep it takes three days for the sand to reach the bottom? would it form a delta?

[@corro202]

Awesome video.

[@ruolbu]

This is so cool.

[@ynntari2775]

5:22 ‒ I'm talking about you, Bosnia and Croatia

[@sp_ce.]

Just a lil' question. How does one move a continent in GPlates?

[@Hammer2000]

Hey you have a tiny typo in your riverine maths sections, you have < (less than) 500 when you wanted > (greater than) 500.

[@djmouton251]

God giving us a walkthrough on how he made the world

[@brenmayhugh]

“Good morning internet” (in my head, “let’s world build”) even if you don’t actually say it...

[@IronFist9595]

yay!

[@alejandroojeda1572]

What about estuaries?

[@WafflesCookToo]

Ah yes. I love rivering

[@amyshaw893]

please, you said you were going do a video about asteroid belts a few years ago, but you still havent done it. when is the video coming?

[@samsargent284]

Ah yes Arroyo

[@simon_gabriel573]

What about estuaries? What are the conditions for an estuary to form instead of a delta?

[@keith6706]

You need the river(s) to flow into a semi-enclosed body of water that's open to the ocean. San Francisco Bay and Chesapeake Bay are obvious examples.

[@rianantony]

the 9 dislikes are rivers who dont like being analized

[@eveningstar7048]

background music is... rly grating. amazing video but that half-audible synth wheeze with no definition just really stresses me out hahah

[@C1914]

He made a mistake. The desert is filled with salt lakes and flats.

[@nicolasinguanti9986]

You forgot the most important part, killing them in the first episode they appear in.

[@hackarma2072]

I miss an exemple of a water gap :l

[@gunjfur8633]

"hanging valleys" sound so mystical

[@petersheppard2173]

They look mystical as hell too

[@aureusknighstar2195]

Yeah, scientific names can be very cool to use for naming fantasy objects

[@Schnabeltassentier]

Yeah, look at Lauterbrunnen in Switzerland, it‘s a U-shaped valley with hanging valleys on the side, and it also served as inspiration for Rivendell

[@feliscape]

Thank you for the idea

[@nestoreleuteriopaivabendo5415]

I took inspiration from Bastard!!, in which the author took rock bands and musical trivia to his world-build. There's a band named Kyuss, which has an album called "Welcome to Sky Valley". How come a valley happen in the sky? Let's take this further!

[@sockpuppett9300]

Finally what i learned my middle school science class in coming into play

[@beaclaster]

"play" like.. rpg?

[@sockpuppett9300]

@@beaclaster it’s useful now I suppose

[@alejandroojeda1572]

When a river cuts through a mountain chain you can expect cities to be built as they can be both a mountain pass and a Port city. Viena IS a great example

[@wolflahti412]

Here's a fun experiment: Build your topography of clay and sand, then "rain" on it from a watering can and see where your rivers form.

[@EggsBenAddict]

Wouldn't that take a while?

[@srikrishnarao1094]

@@EggsBenAddict takes 1-2 minutes max

[@EggsBenAddict]

@@srikrishnarao1094 Very well then

[@VulcanTrekkie45]

So the bigger the river volume, the shallower that formula assumes the river is. I talked to Edgar during development and he said you can vary the width of the river within an order of magnitude or so. For example the Merrimack River is about 300 meters wide at its mouth but the formula predicts 900 meters. This difference is due to the fact that the river is deeper than expected, being about 5 meters deep

[@jasonreed7522]

Alot of the depth is determined by the geology of the medium through which the river flows. For instance a fold or rift may have a hard soft hard band which a river (or glacier) can carve out to make a very deep and skinny channel. Also glaciation basically resets the dirt layer so expect relatively clean water (especially if your draining a lake). Alternatively deep bedrock can make a situation like the Mississippi or Rhine near their deltas where the onlything the river cares about is loose dirt so it may be extra shallow but wide and meandering.

[@AzharaSophie]

8:51 Question: do rivers always flow down mountains? Answer: no, a minority of rivers flow up mountains.

[@somedragontoslay2579]

Technically true, but they do so using the inertia of previously flowing down. That force is too weak to keep them flowing more than a few miles at best. Because of that, it's more common for them to get diverted. That means that most currents flowing upwards are artificial (channels).

[@Kingstar1139]

8:16 You used the less than symbol ()

[@whoeveriam0iam14222]

correct symbol but at the wrong side of the number

[@adamcetinkent]

I kind of thought you'd add the complexity of the majority of the rest of the video into your map, rather than just having it be a "river go down"...

[@dig8634]

I think most of the details explained later on are too small to appear visibly on the map they started out with. You don't really see meanders on a continent scale map, and while that looked smaller, it was probably still too big to see smaller details like deltas

[@tavdy79]

One thing that should have been mentioned: the way people interact with rivers, with each influencing the other. The area where I live has several good examples: Over thousands of years, rivers will deposit large amounts of sand and gravel along their flood plains, in addition to silt. These are valuable resources which humans then dig out, creating quarry pits which usually end up becoming small lakes. If you look along the Nene and Great Ouse river valleys in Northamptonshire and Bedfordshire, England, they are lined with hundreds of lakes - abandoned quarries which now as flood protection by absorbing excess water during heavy rain. As added bonuses, they have also become important recreational areas, and refuges for endangered species like water deer. Human activity can also create much larger lakes intentionally - reservoirs - and these may be the only large bodies of water that exist in some areas so their creation can have a huge effect on the type and variety of wildlife you find in an area. Reservoirs may also change patterns of human habitation. A dormer village that was once a ten minute drive away from a major town or city may find the journey takes an hour or more, so is likely to stop growing. If a river passes through an area of bog, fen, or saltmarsh (acid, alkaline, and salt wetlands respectively) which people then drain to use as farmland, the river can end up much higher than the surrounding land - several metres in some cases - especially if it had natural levees. Once the Nene and Great Ouse reach northern Cambridgeshire, which was originally fen, they quickly end up several metres higher than the surrounding farmland, which has sunk as it was drained, and mostly lies near or below sea level. There will also be drains - artificial waterways used for drainage - created at the same height as the natural rivers, so that the "horizon" is often the next embanked waterway, whether natural or artificial.

[@theohedd289]

Excellent way to spend lunchtime! Rivers will always be the parts of a world I can spend the most time on and still be unsatisfied, so this video is great for me. Thank you!

[@LordRavensong]

BUT EDGAR! What about biforcation??? I'm mostly joking, though that could be interesting to look at.

[@matterhorn731]

Check out the Casiquiare River, which is one of the largest bifurcations in the world. It siphons some water from the upper sections of the Orinoco River into the Rio Negro, a tributary of the Amazon. Research suggests that this is not a stable condition, but is instead a step in the process of *stream capture*, where eventually that entire section of the Orinoco will be diverted into the Amazon.

[@Outfox447]

I've legitimately been trying to figure out how rivers work for days now. How does he always know...

[@petersheppard2173]

research, lots of proper research

[@jasonreed7522]

Probably atleast 3 to 4 weeks of research per video. And lots of note taking. The two best places to start this type of research are wikipedia and google earth (also personal experience can be a good starting point). From there everything should just spiral out as new questions keep popping up.

[@dasik84]

We still don't know where the initial stream appears, the constant source of water. Because if it were just rain falling down, the rivers would exist only for hours or days.

[@Spartacus005]

This is a really good quick summary for Geology 101 students!

[@jessehendrix2661]

For fun I'm programming a world generator which, given a heightmap, will create oceans, rivers, various climates, basic mineral deposits, etc. I'll then create some neural network controlled people with Bronze Age technology, and the availability of resources will depend on the world generation process. Got hung up on rivers, but I think your video might have solved my problem.

[@ElijahDawkins-yb1uc]

Did you ever finish it?

[@jessehendrix2661]

@ElijahDawkins-yb1uc No, but I did have it generate continents, oceans, and lakes, and I simulated erosion. I made a buggy prototype of ocean currents too. The idea there was, along with a wind simulation, to create a sailing simulation. I also made a tree generator with the idea that when you zoomed in on a given point of the world map it would generate a smaller scale map based on the geography. I also experimented with making a map where instead of a single rectangular map it was two circular maps simulating the northern and southern hemispheres. I also made a converter to make a map like this out of a square map and used it to make a more accurate map of earth. That way there was no teleporting from the North Pole to the South Pole. A solution I considered is moving off the top of the map on the left side to the corresponding point on the right side, but that meant the distance was greater from east to west than it was going off the top or bottom of the map. The circular map on the other hand was seamless. But I never finished it, and I've pretty much abandoned it now. It was a fun project though. Maybe I'll get back to it one of these days.

[@nvwest]

This probably won’t cover the way underground rivers work (which is an important location in the story I’m working on) Edit: 10:16 Hurray! 🎉 they were mentioned. I guess the ground composition could be usefull then. Even the short mentioning gave some terms to research further

[@qwertyTRiG]

Karst landscapes are fascinating.

[@_yellow]

Watch the whole video first

[@nvwest]

@@_yellow That’s the second part of my comment.

[@lilyfm7152]

Why did you preemptively comment this...?

[@nvwest]

@@lilyfm7152 because I wanted to :)

[@lennartgimm]

Makes me even more fascinated looking at Europes rivers, especially the Main, Rhine and Danube in the Alps. That must be wonderfully weirdly shaped drainage basins

[@moemuxhagi]

Ooooh ! 😍 Also I hope one day you get to make videos about Auroras that would be so great ❤❤

[@aaronthomas8190]

Watching this is so much more fun than election results!

[@amehak1922]

Woohoo!! A regular video! I've wanted this topic covered forever!!

[@حَسن-م3ه9ظ]

Can you discuss the geography/geology/etc of a world with floating islands? Like.... It has otherwise normal laws of physics, but there's just bunch of islands magically levitating in the sky

[@elijahberegovsky8957]

If only every geography teacher packed so much INTERESTING information in a single lesson… Dude, I admire you!

[@skipp3252]

This was way more in depth than I expected it to be. Well done!

[@dirus3142]

THis is one reason D&D/Pathfinder maps make my head hurt. I know some thing is wrong with the rivers but I do not have the knowledge of why they are wrong. Or, why some of them can work.

[@MarcelinoDeseo]

This is what Iove with conworld: you get to understand geology in general as you design your world realistically

[@liamjohnston2000]

This was a really good video explaining how rivers form and the effects they have on the environment, but I do have some questions about how human cultures would interact with them. First, you mentioned in the video how rivers in drier environments tend to dry up during part of the year. Does this always happen, or will larger rivers (the Nile comes to mind) keep flowing throughout the year and only change in volume? If they do dry up during part of the year, how do the major cultures around these rivers adapt? Second, I know that a lot of work nowadays is put into maintaining a river's course and making sure it does not move. How often was that done in the past? How do changes in river courses affect structures built around them (bridges for example)? Also, how common were bridges in the past, given how rivers move? I would appreciate any information on this.

[@yanagelfand4337]

I was googling "oxbow lakes", found the word "billabong" and then came across the "Waltzing Matilda" song. And it's so freaking beautiful (and apparently so famous, why such famous things in other countries just never reach us?). You never know where random worldbuilding terms could get you, and I'm so grateful for that.

[@PlayNowWorkLater]

I hadn’t really thought how meandering Rivers will affect borders before. Interesting how some disputes may have been caused my natural erosion

[@Drickken]

As foretold in the ancient texts; The creator returneth! (good to see you back)

[@makinishikino7410]

The thing is, the people in his fantasy world actually do see him as the creator... because he is the creator of that world.

[@CatchThesePaws]

Me: I just want some good tips on how to put lakes on my fantasy maps… Artifexian: **pulls out math formula to calculate the width of a river** Me: **confused screaming**

[@aashraychopra2999]

Hey, great video man, but just wanted to point out that, counterintuitively, a river gets faster the further downstream it gets, and not the other way around!

[@casparroist2920]

It gets faster because volume is added, and less of the water's force is used to overcome friction due to a lower percentage of contact.

[@ragnkja]

Not that counterintuitive if you consider potential and kinetic energy.

[@aashraychopra2999]

@@ragnkja very true, combined with the smoother surface downstream, it really isn’t that confusing but the first time I came across it I thought the river was faster upstream due to the more turbulent flow, hence why I said it’s counterintuitive 😅

[@isabela8214]

I think that gaining rivers would probably speed up and losing rivers would probably slow down. I don't know anything about rivers, though, that's just what seems intuitive to me.

[@ragnkja]

@@isabela8214 Even losing rivers gain kinetic energy as they lose altitude and therefore potential energy.

[@francescoiacoangeli2975]

Well you just give me the casus belli I needed to continue my story, Thanks for the "Abandoned meander war". Ah, those riverside fertile flat lands, always causing troubles

[@TheDcraft]

Not your best stuff, though I suppose Rivers are a broad subject so it can't be helped, not everything will be covered.

[@indianna1549]

This might as well have been marketed directly at a demographic of me because it's everything I look for in both an educational video and a worldbuilding one. Great graphics! Entertaining script! Wonderful title! Engaging narration! Making fictional worlds by understanding just enough about how our own world works to apply it in a creative context! I've been a Patreon for well over a year now and I have been blown away by the content you've made in that time. Well worthwhile, for sure.

[@potatolord1234]

i think i already asked this but what do you use for your maps???? at this momwnt im only using paper but it gets rlly hard to work out the biomes, air and water currents n shit... could you help me out???

[@Airoku]

How to learn geography? Just make your own earth and civilization.

[@scarecrow7495]

The timing of this video is uncanny, I was just the other day realizing I don't know anywhere near enough about where to place rivers on my map. Thanks for producing quality content!

[@greenmario3011]

Remember to hide at least one small splitting river to mess with insufferable people

[@aqbrooks7725]

Could you do a tutorial on how you draw mountains like these, my mountains suck and never look as good as this

[@gajusz4372]

theese 7 ppl who disliked the vid be like: idunno i disalike tha rivr

[@NaidenLisichkov]

I still want a video on diseases for our worlds

[@naidentodd-marinov9570]

Yes

[@haydenmaines5905]

I audibly yelled 'NO!!' when it didn't open with 'Good Morning Interwebs! Let's world build;' :p

[@SBVCP]

Now I really want to make a rough estimation with this method, then take the same map, with a rough heightmap and 3dprint it, then shower sone (colored) water into the mountains (or use ice) and see how it flows

[@Lucy-ng7cw]

An oxbow lake is known as a billabong in Australia.

[@JontyLevine]

7:25 Are you sure those are the correct units? Multiplying volume flow rate (length cubed over time) with area (length squared) the way you describe would result in some sort of hyperdimensional volume (length to the power of 5 over time). Unless there are units hidden in those constants that cancel out the extra dimensions. But I can already tell that the formula won't work, because combining two drainage basins of the same size where both receive the same amount of rainfall would double R and double A, which would quadruple the provisional width of the river. Also (and I think that geography teachers do this too, so you're not to blame for this), does it seem a little off to you that provisional width - essentially a measure of cross-sectional _area_ - should be measured in metres, while _depth_ factor is supposedly dimensionless?

[@davidguerin6142]

Maybe the rainfall is in millimetres (or liters per cubic meter, which is the same) per year ? That would make more sense

[@JontyLevine]

That would make a lot more sense, yeah

[@billionai4871]

How straight the river needs to be is proportional to the height difference between the start and end of the river. In the US, most rivers are fairly straight, but in the Amazon, for example, where the ground is basically flat, the river has stupid amounts of winding. You can make a bendy river in low lands, if you so desire. Edit: now that I've seen most of the video, I see you mentioned the bendiness in lowlands, but my point - that a river can be basically all bendy - still stands Also, the basins don't have to drain only by evaporation, they can also drain to the soil, if you have a spongy rock. Sorry, I don't know the correct terms in english, I learned this years ago and in another language

[@mfaizsyahmi]

the word you're looking for is permeability.

[@billionai4871]

@@mfaizsyahmi thanks! The specific one I was thinking was underground aquifer, but I learned a new word now, hooray!

[@traumachild1737]

This is my type of over thinking