You might want to look at one of RobA's scripts here. I am not sure how it fits into 2.8 but might be worth a try. Let us know how it works out.
You might want to look at one of RobA's scripts here. I am not sure how it fits into 2.8 but might be worth a try. Let us know how it works out.
Art Critic = Someone with the Eye of an Artist, Words of a Bard, and the Talent of a Rock.
Please take my critiques as someone who Wishes he had the Talent
I had a thought the other day concerning the interface between rivers and seas, so I thought I'd bring it up here. We have discussed delta formation in fairly great depth, but there hasn't been a more general conversation about how rivers affect coastlines.
To start the discussion off, we know that as a river nears the sea and loses momentum that it can drop silt, which is what causes a delta to form. Usually, the delta will extend the coastline outward, as can be seen around the Mississippi Delta and the Nile. In contrast, other rivers may form an estuary, where the river erodes the coastline away, allowing the sea to move further and further inland. Because the estuary is filled with a mixture of seawater and river water, it usually has lower salinity than the ocean, but higher than the river. Many deltas also have this feature, and in both cases, the water level and level of salinity may be dependent on the tide. In some cases, a river ending in an estuary may actually run backward at high tide, as pressure from the narrowing channel temporarily forces the water to run uphill.
Are there any other interesting coastal formations caused by rivers? Have I got anything wrong there?
Bryan Ray, visual effects artist
http://www.bryanray.name
Posted on reddit's earth porn. A triple water shed point which is quite rare.
"Triple Divide Peak, Montana, USA. The peak shed water to the Pacific, Atlantic and Arctic Oceans"
http://i.imgur.com/IMs8Q.jpg
I like this thread. Understanding physical geography is essential to creating a map of realistic, earth-like landforms and waterforms.
Rivers
These are good rules for a strong foundation. Here are some other things that I've noted at the risk of re-stating something in the foregoing thread. Rivers do drain into the sea, but sometimes that sea is an inland sea, or an endorheic basin. I live in an endorheic basin. I like to think in terms of 'watersheds,' although it's usually easiest just to look where the river is going. A watershed is a family of streams and rivers that eventually all join into the same river that drains into the ocean or an inland sea. Any river in the real world that flows into the Great Lakes of North America, the Great Salt Lake, the Dead Sea, the Aral Sea, the Caspian Sea, or the Baikal, is by definition part of an endorheic basin. There are many more.
In physical geography, not only the landform determines the path of the water channel, but also the amount of water. For example, a river discharging a lot of water passing over nearly flat land will meander in a different proportion to a small river passing over a nearly flat surface. The truth is that the rivers in my world are probably all violating the actual 'wave' that they should form since I have neither the ability nor the inclination to calculate this. However, the general principal is that the more water that is discharging through the channel, the bigger the meanders are. Geology has a whole sub-discipline for shapes of rivers called river morphology or fluvial geomorphology and it is generally way more than I want to know, but it is nice to be aware of.
On my Asdar world map, mountains are denoted by simple lines since the scale is large (1 inch represents 80 miles). For this reason, I can get away with the shape of my rivers. When I make a regional map and define the contours of the landforms, the rivers must observe these landforms as they flow ever downwards. I must also take into consideration the climate and the amount of rainfall.
It is possible for a river to drain a great body of water into the sea. The St. Lawrence River drains from Lake Ontario into the Gulf of St. Lawrence (North Atlantic Ocean).
The Thames River (346 km) is pretty short compared to the Nile, the Amazon, or the Mississippi. However, due to Britain's notorious rainfall, it is a very broad, navigable river and its average discharge is about 66 cubic meters per second. The Ishim River (2,450 km) in Kazakhstan, is about seven times as long. Its average discharge is about 56 cubic meters per second. The size of the watershed and the climate are the basis for how much water a river must discharge by the time it reaches the ocean or the inland sea into which it disembogues. Seasonal rainfall can also change the behavior of a river as residents around the Mississippi well know. Arroyos or Wadis in Arizona and Arabia that are dry or mere trickles most of the year can become raging rivers during sudden thunderstorms that cause 'flash floods.' I indicate Wadis on my Asdar map with a dotted line.
The Shadew River (pronounced SHAY-juh) on Asdar is inspired by the Brahmaputra-Ganges River in the real world. Rain and glacial meltwater feed into this river for probably over 3,000 km. It passes over the division of tectonic plates, cuts a nice canyon, has some glorious waterfalls, and then finally passes through a great delta into the Pallathantic Sea. The delta area is probably too large with regard to the river's length. I justify this by saying that the tectonic rising of the subcontinent of Pytharnia has forced the great discharge of the Shadew River to make new channels over many tens of thousands of years, so the river cuts down as the earth rises up. The Shadmouth, or mouth where the Shadew River enters the delta is easily over two kilometers wide. The nation of Bangladesh is striped with the braids of the Ganges River, however, it is relatively flat.
Inland bodies of water
I take the other extreme and tend to have lots of lakes, perhaps too many, in the world of Asdar. I am careful to place them in climates where there is sufficient rainfall. However, the 'Sea of a Thousand Curses' is quite large and rests in a desert region. Its saltiness is somewhere between the ocean and the 'Dead Sea' of earth. It has been shrinking since the Ice Ages, but is still quite vast for an inland sea. I justify this by saying that it has survived from before the end of the Ice Ages.
The definition of "endorheic" is that the basin is closed, not that is part of that list. So it's not "by definition". If an outlet formed from the Caspian to the Black Sea, the Caspian would cease to be endorheic. As you point out a little later, the Saint Lawrence drains the Great Lakes into the Atlantic, so the Great Lakes watershed is not endorheic. Lake Baikal also has an outlet in the Angara River, a tributary of the Yenisei River, which flows into the Arctic Ocean.Originally Posted by Trismegistus
I didn't know that about Lake Baikal. Thanks for pointing that out. I should have caught myself with the obviously inconsistent statement about the Great Lakes. I've been looking at fractals lately and river systems are sort of like that, especially as you look at them in closer and closer detail.
Last edited by Trismegistus; 06-15-2014 at 01:19 PM.
THANK YOU!
This was one of the best written, easiest to understand articles I've ever read. Especially considering the complex science of river formation, I cannot believe how easy this was to learn thanks to the author's ability to write so well, concise but detailed.
Knowing how rivers form IRL and the Do's and Dont's of the river police, actually made it EASIER to add my rivers in my map.
It would have been a headache to just randomly place them around the map, and very hard to look natural.
Instead, it was easy! So easy, and on my FIRST attempt they looked professional!
I cannot thank you enough for this article.
Very interesting post. I always thing about how to place rivers in my maps and sometime its a bit crazy how y do it. Now i know how to do it. Thanks for the post
After reading all this I came to a conclusion to make realistic river and lakes:
Follow the 3 steps to have regular rivers.
If you want to make exceptions, use the google maps/earth (or another real world map) and look for something that is what you are looking for, and you probably find your exception hidden somewere in our world.
Nice thread
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