Thanks! I've been a fan of the Guild for ages.

Here's another real-world island, with some topo, that might be more immediately helpful (for me, anyway.)



If I take a closer look, a number of useful points are illustrated:



  • The way the lakes are nestled in to the contour lines. They're local minima of elevation, to lapse into mathematical jargon. (Well, almost. If they were true local minima, they wouldn't have any discharge river.)
  • It's easy to see that the rivers cross the contour lines at right angles. They follow the gradient, to again bring out the jargon.
  • The deformation of the contour lines near the rivers that reflect the river valleys (technically, the slightly-dirty-sounding 'invagination'.)
  • The way the ridge-lines function as watersheds.
  • Chain lakes.
  • The rivers running through steeper terrain (where the contour lines are closer together) are straighter, in general, than those in the flatter terrain.


I feel like I'm learning a lot already.


Cheers,
Roger