Well, studying the lay of the land, i feel this seems reasonable.
I've drawn some mountains, and the darker area is my realm. With a volcano with the fortress capitol to the west.
Large parts of the borders are mountains, but almost equally large portions are more regular borders.
I thought the winds primarily blew to the east. Therefore the ash formed like this.
In my exmple i gave myself some coast. But if i have grabbed too much land, i've added the blue lines, and will be content with just what's to the left of those.
My thought was, lots of land, but not very lucrative land. And the population is centered more around the purple cities.
Thoughts on this are welcome.
Oh, and what program was used making the map?