[Terraforming] Rivers

Discussion in 'Inspiration & Worldbuilding' started by Andy_Jones, Aug 29, 2017.

  1. Gonna kick this thread off with a nice GIF showing how incredibly fast Rivers change their path (in flat terrain):
     
  2. Wazgamer

    Wazgamer Lord Paramount of The Riverlands Maester

    So how to make rivers?
     
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  3. Elduwin

    Elduwin Maester

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  4. Enah

    Enah Mother Nature and Lord in Bandallon Maester

    apparently there are no rivers in Albania, Bosnia/Herzegovina, and Montenegro, lol. in seriousness, great river maps eld!
     
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  5. Fin

    Fin Builder

    ok, I'll post this here, though you'll notice it's an incredibly broad database for pretty much everything which can be mapped in Switzerland.
    https://map.geo.admin.ch/?lang=en&t...&zoom=1.1338561897747244&catalogNodes=532,614

    Just a quick how to navigate the site: On the left you should see a menu bar. Navigate to Geocatalog and then to Nature and Environment. Then knock yourself out... That link just shows the water networks of switzerland, which in this post is the most relevant. Perhaps someone can find a use from that, or from some other tab on the site.
     
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  6. I would like to remind everyone doing river terraforming not to go overboard on the technique of meandering. Since we use it for only about a year now, and while it is realisitc to have many meanders in flat areas, for example towards the coast, we should not overdo this in more hilly terrain and way upstreams.

    [​IMG][​IMG]
    We know this is what meanders can look like. But the Amazon basin is extremly flat, with only meters of height difference over hundreds of kilometers distance.
    [​IMG]
    But look, here are meanders in regions with large height differences! Yes, that is true. But as you can see, the meanders are actually shaping the valley, with hills or even mountains between the different meanders. These are not meanders with sand or pebble banks in between. (Like currently at stoney sept which made me post this, and in a few other projects around the server.)
    [​IMG]
    Just to invalidate my earlier arguments: We can find valleys with meanders within them in the mountains as well. But please, keep in mind these are rare cases. Which brings me to my main point:

    It is easy to find examples for awesome terrain in the real world, as nature does incredible things. It is also part of creating a fantasy world to dare shaping the new. But I think we need to think about a balance in all this. Both for realism and to create a good experience to people that will actually roam our incredible map. And with the meandering, I think we are about to go overboard.

    Redfort is a great example for a realistic place to implement meanders. But if you check on the dynmap, the meanders will only start a few blocks above sea level. With the ocean this close to high mountains the whole system feels realistic, and as it belongs there. But once a traveller will have to get across numerous meandering rivers stretching for hundreds of blocks all over the map - which are using a hell of a lot space at the same time - he might not think about it as something nice anymore, but rather something annoying.

    Basically, this goes for everything. If we overdo anything, or more importantly, do it in implausible ways or places, it will bore the player and the world will feel less vivid.

    So please consider if it is reasonable to add large meandering rivers to the location of your project. I'd rather like this being implemented in very flat terrain and our main rivers. Most of the time.
     
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  7. EStoop

    EStoop Faux maester Builder

    I think the main problem with this is that "my project should be special, other people can do the basic stuff" is the prevailing thought process on the server. I have yet to see a project app with a properly modest or even shitty castle, poor lands and boring nature. Most projects are based on the most extreme, top-tier amazing examples for nature, castles and anything else.
     
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  8. Enah

    Enah Mother Nature and Lord in Bandallon Maester

    I see boring nature a lot, fields and farmland is the boring nature. Forests are boring. I agree with you about top tier castles being a huge issue,especially when some have more luxuries than the great houses! However this thread is not the place to discuss that and we shouldn’t deviant from the topic
     
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  9. EStoop

    EStoop Faux maester Builder

    What I was trying to say is that the lack of balance mentioned by Andy is the result of a certain mindset that is not unique to nature.
     
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  10. Enah

    Enah Mother Nature and Lord in Bandallon Maester

    Oh, that was more of a reminder to myself than you lol i'm definitely sad with how some of the rivers are shaping up. It has come to the point where everyone wants meandering rivers and brooks, without any causation or geological reasoning. We've also got rivers still *new ones too* which have no water sources such as springs or natural collection points for creeks and rivulets, that could account for wide, deep rivers. i'm still puzzling over the one @Thamus_Knoward made from Ferren to the Blackwater... Especially as it goes through valleys but has no smaller tributaries or feeder streams.
     
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  11. You wanna discuss something with me @Enah? Shoot me a message pls, its pure happenstance that I find jabs like this if my name isn’t tagged.
     
  12. Enah

    Enah Mother Nature and Lord in Bandallon Maester

    It wasn't jab.
     
  13. I’m happy to be held accountable for mishaps so just talk to me instead of about me ;)

    Which stream are we talking about here? A finished stream from Ferren to the Blackwater? Help me out with a screenshot?
     
  14. Enah

    Enah Mother Nature and Lord in Bandallon Maester

    The big river, it lacks feeder streams, some lil irrigation streams from the fields or a couple from the hills are jsut needed. that's all, i meant no offence truly.
     
  15. Oh the one crossing Hawthorne terrain? None taken, you do realize that its very much a WIP right? Unless of course Lemon or antalex have proceeded with it.

    I’ve outlined the full extent in my geomorphology thread a while back. I’ll dig that up once I’m off mobile.
     
  16. Enah

    Enah Mother Nature and Lord in Bandallon Maester

    I thought Lemon had been working on it recently but knew it waqs wip, just didnt remember seeing any plans for the streams
     
  17. I have no plans to work on the river myself. I was under the assumption that @Thamus_Knoward was going to do it, and that was kinda one of my conditions for it going through Hawthorne in the first place.

    I've pretty much been working on everything but stuff that would interfere with that river, including Ant's and my initial stream to lake combo, which is not connected to Thamus' river.
     
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  19. Sajjetta

    Sajjetta Builder

    Hi guys and girls, Ive seen the detail going into this build and having spent many years studying geomorphology and thought you might find a basic guide to Rivers useful? There are of course many intricacies, so this is just the broad brushstrokes.


    Lets start with how water gets overland to a river, it called overland flow, eventually flow congregates to a lower point becoming a rill, then a gulley/stream. Some water goes into the ground, and flows through the surface. When this gets forced to the surface you get a spring, or if its in the bottom of a dip/valley a permenant river. Every significant lowpoint in a surface will have a watercourse, be it permenant or ephemeral (seasonal with the rain). Also remember that all wet vallys should have a river, bit the river may not have created the valley in which it flows, techtonics and glaciation can do that.


    Now for generic riveryness before moving on to more specific features.


    First a rivers long profile is key. http://www.geography.learnontheinternet.co.uk/images/rivers/LongProfile.png


    The upper course is the steep section down the mountainside. High energy bit small streams that can move large boulders at high flow (with the assistance of gravity). Think waterfalls and pools bouncing down a hillside.


    The middle course is where the river profile curves in the mountain piedmont. Here rivers tend to run through pools and riffles (rapids) as it 'steps' down. Its course will be generally straight with a bit of sinuosity. It is also loosing its carrying capacity so we are now looking at cobbles pebbles and gravel as it starts to deposit material larger stuff first.


    In the lower course the profile tends towards infinitesimal flatness. Here is where we get meanders. By now the river has dropped its heavy material and is carrying just silt and sand. This means it has some excess energy which it can use to erode laterally. Looking back at the long profile this winding lengthens the lower course and so shallows the gradient, helping the river move towards that perfect curve.


    The river mouth, where it flows into a larger body of water, (sea, lake, a bigger river, groundwater)


    This profile can re occur (in part or in full) several times over a rivers full course. Think, underlying terrain stepping down, base level change. So the big long profile gets made up of several smaller ones. You can also look at the actual landscape and profile compared to the ideal curve to see where a river should be eroding downwards (steep gradient) lateraly (shallow gradient) or depositing (when its below the ideal curve)


    On to features.


    Meanders

    Everybodys favourite bendy river bit. As mentioned above these tend to occur in the lower reaches of a river where several factors combine; to start with excess energy allows them to erode sideways, but we also need to look at if the land it flows over is soft and easily eroded, and flat and wide, or confined at all, to determine how much a river can meander. Less energy and harder to erode is more static, more energy and easier to erode leads to oxbow lakes and palimpsest (overwritten) landscapes. The key for the latter is remembering that once a river has broken through and found a shorter course it will follow it and abandon the old one leaving a lake or dry scar, unless it was a recent high flow occurrence on a hard to erode surface in which case the new cut will be a dry scar.


    Braided river channels.

    Two main causes for this. The first is seasonal instability, bars (banks of deposited material) stick out during low flow and get re submerged at high flow. If low flow is the norm then more material can build up around the bars, turning them into more permanent islands, after enough time stabilising plants will grow. The second cause is in stable flowed mountain rivers as they enter the piedmont (middle course) the change in gradient leaves the river unable to carry its larger material and this gets deposited en masse, again causing splits and joins of river in a wider channel scar.


    Deltas

    These occur when a river discharges into a larger body of water such as the sea or a lake. Here the flow spreads and slows, causing it to drop its sediment. If the body of water is shallow, calm (enough to not be too erosive) and river flow not too fast/ sediment level nice and high, then these deposits build up causing the river to split up into many distributry channels.

    Fans like those in death valley are a similar principle where steep mountain rivers spread onto a wide flat valley floor.


    Lakes.

    A big pool of water caused by one of several reasons. A geological dip in the terrain that gets filled up until the water flows out through the lowest point in the surrounding terrain. A dam/weir blocking the water, this can be natural where fans/ glacial deposits, landslides etc block a valley. Another way to back water up is by restricting flow by a narrowing of impermeable hard to erode terrain, if inflow is grater than what can get through then the water will back up to form a lake. In general there will only be one lake outlet channel, its possible for several similarly low points to form several channels, with inflow keeping levels high enough to maintain them, but thos is an unstable situation, when one erodes lower than the others it will dominate and eventually become the sole outlet. I tried to find an example of a multi outlet channel but couldnt.


    Canyons and deep valleys.

    Two main causes. A lake has built up flowed over a low point and rapidly eroded a straightish deep channel (ie afton canyon california). The second more often seen is where a meandering river on a flat plain starts to erode downwards because the level of what it flows into has lowered.


    Finally a word on flow state. When rivers flow high its because there is an ample source of water, so look at what your rivers source is. Glacial flow peaks in late summer where the melt is highest, mountain snow melt in the spring as it heats up but before all the snow is gone. Temperate rivers flow highest in winter rains, desert ephemeral streams just after a thunder storm as a flash flood, and tropical rivers flow highest in summer when the sun is overhead creating the biggest storms.


    The key is to look at the land your river flows over and the source of its water to work out what it will do and where.

    Hope this pasted in ok, feel free to shoot me any questions.
     
  20. Thanks for the great writeup!
     
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