Quote Originally Posted by waldronate View Post
A catchment is a function of a atream of river. I don't see either of those on the map. If your goal is to determine how rivers will flow based on your map, I recommend simply drawing them from the mountain range to the nearest ocean. Smallish enclosed areas are likely to have internal drainage. A scale would also be helpful in determining the potential quantity of flow.

I built a small height field and ran a river computation on the results. The white areas between the river systems would denote the boundaries of the major catchments. I had planned to attach the file, but the upload manager didn't seem to want to be cooperative (perhaps it was an IE9 problem). http://www.ridgenet.net/~jslayton/Ab...Catchment1.jpg has the intended attachment.

However, it's often easier to do river routing by hand than it is to fake it like this.
That is a lot of rivers my friend. The scale I am working with now is 1 pixel = 1 mile. It's only representative, and it's my first map so it's also experimental. I am just trying to coordinate all of the things I have learned about creating a realistic map based on earth-like qualities. The rivers I will draw are only be major ones until I do the regional maps. Those will contain 90% of the detail.

One question: When you reference small enclosed areas are you referring to the ares where the mountains are close together?