Some people don't like making their edges separate entities, they don't like placing their map changes in the corners of their geomorphs. For those people, I present a geomorph system like this...
It might be a swamp, like the marshes that Gollum leads Sam and Frodo through after the fellowship of the ring breaks up.
It looks pretty simple, and could probably do with a bit of colour, but it's basically a specialised three-phase system...and there is a degree of trickiness in its execution that you have to be careful of.
Let's say the stippled fragments through the map are rocky outcrops in the swamp. Each of these is self contained within a geomorph. The three edge types of the geomorph system are "open water", "left bank" and "right bank". If we have the described edge at the bottom of the geomorph, the "left bank" has land of the left and water on the right...and the "right bank" has land on the right and water on the left.
Unlike previously described systems where an "open" edge matches an "open" edge, and a "road" edge matches a "road" edge, the catch with this system is that "left banks" can only match up with "right banks" when you assemble the geomorphs into a map. Thus you need roughly equal numbers of "left" and "right" banks otherwise you start to run out of options for assembling the final map.
It's not a huge issue, but something to consider.
If you are making 3D geomorphs for wargame terrain, you might substitute "left bank" and "right bank" for "left hill" and "right hill", the same situation applies.
Ultimate Table Top Terrain)
(Edit: I've just looked back at the geomorph image for this post and have noticed that it is actually a four phase system. It has edges that are "open water", "open land", "left bank" and "right bank". Also, since I've had some queries regarding the concepts of "left bank" and "right bank", I'll expand these ides and give some better explanations in a later tutorial.)