Trying to make a map[HELP]

[Pillipilliman]

I imported a heightmap of my own making and I was greeted with this sight, what’s the usual procedure to remove all the buildings, tiles and cities from the ocean? Also what shades of black gray and white should I use to not have the coast be a 30 kilometer deathdrop to the ocean?

 

[Pillipilliman]

Please, I really don’t know how to edit provinces.bpm into one single province for now without causing a crash. I’m trying to make a map based on thawed Antarctica.
So far I've solved most of my issues but the only one I can't really solve is provinces.bpm and the trees and cities in the ocean