Thank you all for your nice comments !
@ Jurri : provinces with villages are considered to be farmlands. If I'm not wrong, #55 is only a desert beach (= waste)and #48 contains a village of fishermen and a port. That's the difference.
About #49, do you suggest that the whole forest would be unreachable ? The problem is that it is an important magic site (forest of golden leaves).
@ Ironhawk : the terrain colors mean nothing.
They are just different countries, if you like. The color of the buildings change just the same way.
Thanks for commenting.