How to get your rivers in the right place

[fol2dol]

Thanks, this is a very usefull tutorial.

[Tonnichiwa]

Well, I basically live in wonderland when it comes to this kind of thing as the Skagit River flows down from the Cascade range in Canada to the Cascade Range in Washington State, USA, before finally leaving the mountains and making its way to the Puget Sound. 8 miles before it gets to the Puget Sound it splits into two separate forks and then both of those forks form two different Delta's. The island created by this is called Fir Island and is 15.50 Square Miles (40.14 KM sqared).

But where I live is weird anyway because from the town I live in if you travel 15 minutes west you find yourself at the Puget Sound, an entrance to the Pacific Ocean. If you travel 15 minutes east you find the Cascade Range of Mountains It is great stuff for mapping because you could easily imagine Dwarves and Orcs & Goblins inhabiting the mountains and Elves could easily be living in the forests below the mountain range. Mount Baker, one of the larger mountains, is 10,781 feet (or 3,286 M), couldn't be content with just being a mountain either..oh no...it had to go show off and become an active volcano too! And then it got lonely and brought friends! so there five stratovolcano's in the state where I live.

Here are two pictures, one showing a map of the Skagit River and it's split, and another showing how close the Volcano is.

Also, count how many lakes there are on that drainage basin map. I've counted at least 30. And that's in a relatively small area.

[RobA]

8 miles before it gets to the Puget Sound it splits into two separate forks and then both of those forks form two different Delta's. The island created by this is called Fir Island and is 15.50 Square Miles (40.14 KM sqared).

...well, technically the only reason the split exists is because of extensive human intervention by the construction of dykes
(reference http://www.skagitcounty.net/Envision...n_overview.pdf )

and the entire area, including Fir Island, is all a part of the delta (from https://en.wikipedia.org/wiki/Fir_Island_(Washington) )

The Padilla Bay Center provided the attached probable map of the area of 10,000 years ago.

The Skagit River once entered Puget Sound at Padilla Bay, but sometime during the past thousands of years, its mouth shifted southward into Skagit Bay. Bayview Ridge to the southeast of Samish Island, was also once an island, like Samish Island, before delta marshes filled in this region.


-Rob (it doesn't say River Police in my avatar for nothing) A>

[Tonnichiwa]

While they did extensively modify the river during the late part of the 1800's and the early part of the 1900's it is well known around here that the split in the river there is natural. It wasn't caused by the damming and the dykes and all of that. It was there before any of that happened The village of Skagit City, was actually built right where the river forks. It was built there because the river forked there. But I didn't know it was one delta, nor anything about it switching. Still, it is a very visible split and it is totally natural.

[Knighthood]

This is very useful information, reading through a lot of this is a huge asset for designing how terrain contours and how rivers typically go for the path of least resistance.

[NeonKnight]

Blast from the Past, but get a load of this!

https://en.wikipedia.org/wiki/Two_Ocean_Pass

[Redrobes]

Hi Neon - good to see you around. This was posted about in #119. Its in the Yellowstone region and continental divide so it is an unstable area and brand new geologically. After a while it will settle to one or the other. In this case I expect during that time the earth will move and it will continue to be unstable. But I guess given a small enough measurement theres going to be a bit of a slight blur at the very edge of any catchment area.

[XCali]

I don't know if this has come up yet. But I was wondering about River bifurcation, where a river does split sometimes?

The statement that rivers never split(Aside from deltas) has bothered me for some time. So, I was thinking what happens when a lot of fast moving water hit a rock and is forced to split? And then I looked it up and came across River bifurcation, which is an actualy term for these kind of events happening.

A good example is the 'North two ocean creek' at the parting of waters part. This is a fascinating river. That water ends up in two separate oceans!

So it is not never, deltas happen and in certain cases higher up splits do really happen. So, in how one should use it? The general is then, that rivers don't split MOST of the time, but there are exceptions.

[Mouse]

I don't know if this has come up yet. But I was wondering about River bifurcation, where a river does split sometimes?

The statement that rivers never split(Aside from deltas) has bothered me for some time. So, I was thinking what happens when a lot of fast moving water hit a rock and is forced to split? And then I looked it up and came across River bifurcation, which is an actualy term for these kind of events happening.

A good example is the 'North two ocean creek' at the parting of waters part. This is a fascinating river. That water ends up in two separate oceans!

So it is not never, deltas happen and in certain cases higher up splits do really happen. So, in how one should use it? The general is then, that rivers don't split MOST of the time, but there are exceptions.

That statement about rivers never splitting isn't true. It can't be for the phrase 'river bifurcation' to exist

This is a link that Redrobes gave us a few comments ago.

And this is another one - again from Redrobes

The fact of the matter is that it is so incredibly rare that to use it all the time would be as misleading as continually drawing maps showing pink lakes (there's one in Australia that is occasionally pink).

[Momotron]

Some great advice, I had to do a lot of searching on other factors with water such as the different types of bodies and it's been influencing my map. this was a nice resource.