Gensokyo Terrain - WIP

[Katrix]

Hello, I'm from a minecraft community called Yukkuricraft. We have a huge mape of a place called Gensokyo that you can walk around in. While we quite like the current map we have at the moment, it's not without it's problems. The base terrain was made with a cloud noise system, and that's it. This means that the map can feel a bit boring at times. That's why we have decided to remake it, solving this and many other problems. We have been a bit unsure about what decisions to do tough that would be realistic. That's why I've come here to ask about advice.

The main problem we have at the moment is with our river(s). At the moment we have a river with to beginnings and no end. That's not very realistic, so we have to proposed solutions at the moment. Either we can have the water just dissipate in a big lake, or we can have it go to an area with a geyser, which the proceed downwards underground quite a bit. Which of these would be the most realistic thing to happen. The geyser have the advantage of being nearly dead center in the map, while the lake is a bit more to the side.

Here is a draft of approximately how we want it to look. Any other suggestions.

map.png

Here is my progress at the terrain so far. Both a representation of height, and a more stylistic representation. I don't want to really touch anything else as the river will determine quite a bit where the rest go. Any improvements I could do on the mountains?

mapheight.pngmapstyle.png

[tolcreator]

It's a bowl shaped depression, so AFAIK you've got 4 options for a river:

1) The water rises into a lake until it finds an outlet, then settles at that level.
2) Evapouration within the bowl is greater than the inflow of rivers feeding the lake, leading to an endothermic basin. The resulting lake can be very salty, may be seasonal, and may have salt flats around it.
3) As 1, except that the outflowing river carves a canyon, which eventually drains the lake.
4) The river exits by a sinkhole or cave, emerging as a spring or from a cave on the other side.

For an example of the canyon option, see the Wallula gap in Washington State, USA. For the salt lake option, well see Great Salt Lake, Utah, USA. For the cave option, see the Sirion river of Beleriand in Tolkien's Silmarillion. I'm not aware of any real world examples :p

[Chick]

Lakes always have outlets, so having your river "dissipate in a big lake" is not a solution.

Geysers are not water sinks, they are water sources. Underground water heats and erupts from the heat and builtup pressure. Water never flows into geysers, so that is not a solution.

The best solution would be to have your rivers simply flow off the map to the out-of-sight sea in the far distant part of the world

[tolcreator]

Sorry that's "Endorheic" Basin, not Endothermic.
http://en.wikipedia.org/wiki/Endorheic

[CaptainJohnHawk]

Well in the world of Minecraft, rivers don't follow realistic paths. A waterfall can flow into a 5 foot hole, and that hole would never over flow.
So as far as his river placement, the advice doesn't really pertain to what he is doing.
I think the mountains are fine as well. This community will give you realistic terrain advice, that can be extremely helpful. However, for the world of Minecraft, it is really up to you on layout.

If you wanted a critique of the mountains from an artistic stand point, I think they are fine.
A formation like this would rarely appear....unless it is a monstrous volcano. However they are pleasing the eye. Maybe the resolution could use a bump.

Cheers!
Capt.JH

[Chick]

Endorheic basins, commonly called Closed Seas, are actually very rare and require very specific circumstances to exist at all. The evaporation rate must exactly equal the water input rate. If input is greater, the lake fills and flows out an outlet. If input is less, the lake dries up. To have the exact conditions for a persistent closed sea, you would have to make a lot of other things just right on your map. It's not worth it, just give every lake an outlet

[Deadshade]

Actually the end of a lake where evaporation exceeds inflow is an oscillating shape.
Let's consider a cylindrical lake of volume V.
The evaporation depends on temperature and temperature in a year can be described broadly as varying like Ta + sin(f.t) where Ta is the average temperature.
So the evaporation during the year can be approximated by E = a + b sin(f.t) with a and b some constants - this means that the lake evaporates more in summer than in winter.
To simplify we can consider that precipitation and the rivers' inflow is a constant K

Then the variation of the volume of the lake in time dt is : dV= Kdt - (a + b sin(f.t)) dt => dV/dt = K - a - b sin(f.t) => V = (K-a).t + b/f cos (f.t) + integration constant.
And it appears clearly that the term (K-a).t will want to bring V to 0 (lake dries out) while the term b/f cos(f.t) will oscillate.
Depending on the detailed values of K, a and b the lake will dry out more or less fast and then start to seasonnally oscillate - dry in summer , water in winter.

In a more realistic model where the lake is not a cylinder and the precipitation + inflow is also oscillating, the evolution will be slightly different but the end result, e.g dry out and then oscillate is the same.

[CaptainJohnHawk]

I love how every topic that even remotely talks about rivers, people jump all over their extensive river knowledge.
The question is about mountains. He even states he has no questions about rivers.

[waldronate]

The question is about mountains. He even states he has no questions about rivers.

Mountains and rivers are inextricably interconnected here on the home planet. Plus, the question "Which of these would be the most realistic thing to happen" after a discussion of rivers might hint that he has a question about rivers...

Having a river disappear down a hole (with or without a lake above it) is plausible for karst-type terrains. Uncommon, but plausible. Such rivers are also unstable over geologic time. Removing a river through evaporation requires either a very dry climate for the river terminus or sufficient geothermal resources to boil away the river (picture huge clouds arising from the terminus of the river); a canal through a tunnel also works if you're not averse to an intelligence modifying the situation. A small water gap out of the mountain right is also reasonable.

In all cases, though, it's hard to say what the final results would be without an understanding of scale (if it's 100 miles across, the suggestions will need to be different than if it's merely 1 mile across).

[Deadshade]

I love how every topic that even remotely talks about rivers, people jump all over their extensive river knowledge.
The question is about mountains. He even states he has no questions about rivers.

Well I have actually read something quite different. Namely :

The main problem we have at the moment is with our river(s). At the moment we have a river with to beginnings and no end.

I guess that's why people found the discussion about rivers and lake outlets appropriate.