Hi,
An user of SBuilder (thank you Horst) called my attention for the global database of land use:
http://www.gvm.jrc.it/glc2000/defaultGLC2000.htm
You can import data from the any part of the globe. I downloaded the Europe map which defines 17 types of land: from metro areas to ice areas. I made a project that you can use to generate landclasses with SBuilder. Users interested in other regions will be able to assembly a map like the one I made.
Here is a picture:
The projects (and map) are available at:
http://www.ptsim.com/downloads/europeland.zip
You need SB version 1.06a
Luis