How to get your rivers in the right place

[EDG]

Very interesting stuff - I had no idea about most of this, but it all follows and makes sense when one thinks about it.

I have a couple of questions:

- It looks to me as if the lake would drain to the right in your example anyway, because it looks like the terrain rises up to the yellows/oranges just off the the left of the map. So the fact that it does do that makes sense to me. I'm not sure what the river in the bottom-left quadrant is doing though, it seems to fill into the lake and then the lake retreats from it into the top half of your map and then drains to the right? So where is the river water going from the bottom left while it's doing that, is it just seeping into the ground? (also, what software are you using to do the simulation?)

- One thing I've found curious in the real world is northern canada - if you go look at it on google maps ( http://maps.google.com/ ) you'll see there that a huge swathe of the country around Hudson Bay, is covered with small lakes (you can see this in the map mode really clearly). Where do all those come from? It looks to me like the water table is above the land surface here, is that right? Or is something else going on? (e.g. permafrost in the ground is having an effect?). Actually looking at it, northern Ontario nearest Hudson Bay is actually lacking these small lakes (there are several rivers going to HB instead), and the same goes for southwest of HB, but to the east and west and northwest of HB we're back to lots of lakes. I suspect the geology has an effect here (is the precambrian shield that makes up a lot of canada impermeable, maybe?). That may be one thing to explain here too - the effect of permeable vs impermeable rock that the water is going over.

Thanks for doing this anyway, really interesting stuff!