Thread: Geographical theory.

Originally Posted by Zen Clark

I'm am planning on starting a
What causes rivers to form and in what directs would they travel in, besides down?

The basic "rules" of rivers:
* They always flow downhill, never uphill
* They take the path of least resistance. "Resistance" means how much erosion the flowing water would need to cause in order to shape a path through the terrain: A river will find it much easier to run along the center of a valley than to plow through the surrounding hills. On flat terrain the river is more likely to head where the soil is softer.
* Rivers start narrow on the highlands, and become wider as they reach lowlands and head toward the coast. Rivers crossing relatively flat terrain tend to meander (doing zig-zag turns).
* Rivers almost never split - tributaries flow into the main course, not out of it. The major exception to this are deltas, where big rivers reach the sea.

Originally Posted by Zen Clark

How much do tectonic plates affect the formation of continents, and how are they themselves formed and shaped?

Plate movements can split and merge continents, though this of corse happens extremely slowly. They also form mountain ranges (where two plates collide) and rift valleys (where the plates depart).

There are numerous topics here, far too many to link them all up, on such things and a quick forum search will answer all of your questions.

This is a good place to start: http://e23.sjgames.com/item.html?id=XRPFREE2

I recommend an internet search on the term "physical geography".

The most realistic and accurate fictional maps are the alternate timeline Earth maps. They tend to be very plausible in terms of physical features. The best fictional maps are, in my opinion, the ones that best support their story. They may have physically implausible features like a mountain spire hundreds of miles high or oceans that fall off the edge of the world, but as long as they support the story and are self-consistent I find them very good.

The essence of mapmaking is to maximize what's important to the purpose of the map while minimizing what's not important. If your map is about physical accuracy then the capital city won't be more important than a small village. If it's a typical cultural map, then govenmental subunits, navigational aids such as roads, and barriers to trade such as mountain ranges will feature prominently. Finding the perfect balance is tough.

What can be used to find the right balance? The concept that the map is based on is still deep in the making, and I'm wanting to work on map that is both physically accurate along with being something that I can based some of the cultural aspects on.

Originally Posted by Zen Clark

What can be used to find the right balance? The concept that the map is based on is still deep in the making, and I'm wanting to work on map that is both physically accurate along with being something that I can based some of the cultural aspects on.

A Magical Society: Guide to Mapping (Linked to above) uses the idea of being a lazy deity. You have the magic to make impossible things happen, but you don't want to waste it on trivialities. So if something doesn't need to be magic, it shouldn't be, but if you need an impossibility, you should include it, and then work the natural consequences of it out.

For instance: Rivers don't flow between oceans. Unless there's a good reason for magic to cause a river to do so. In that case, the river would have salt water. Unless there was a reason to invest further magic to desalinate it.

I learned a lot from studying this map:
http://www.boqueteweather.com/images...limate_map.jpg
The patterns keep repeating--what happens at different latitudes, differences between East/West coast of continents, effects of mountains, how jagged coastlines are more likely in areas of high rainfall (esp. w/glacier effect at high lats), etc.
This of course assumes Earth cosmology. Change size/distance from Sun, orbit shape/period, planetary size/composition/density (gravity), axis tilt, etc., then you have to make a lot of educated guesses, this might help:
http://www.cix.co.uk/%7Emorven/world...dex.html#intro

Originally Posted by Dogzilla

I learned a lot from studying this map:
http://www.boqueteweather.com/images...limate_map.jpg
The patterns keep repeating--what happens at different latitudes, differences between East/West coast of continents, effects of mountains, how jagged coastlines are more likely in areas of high rainfall (esp. w/glacier effect at high lats), etc. ...

That picture definitely is interesting. It should be fairly useful.

Originally Posted by Dogzilla

... this might help:
http://www.cix.co.uk/%7Emorven/world...dex.html#intro

That article is probably the best one I've seen on map creation. Not many articles go into that much detail, although one with even more would be awesome.

This is a pretty low tech suggestion but if you are having trouble finding the info you need on the net I would suggest maybe taking a trip to the library, or even just spend an hour or so at a bookstore. I have an old text from an Earth Science class I took in university that I refer to if I have any geography concerns.