Hi,
I’ve found a little program that is used for the creation of virtual landscapes.
It has a function called seed that generates terrains that are mainly flat.
These flat areas are separated by small seems of mountains.
The following part of this terrain could be used as heightfield:
After scaling and importing to Easygen:
DL of this heightmap scaled to 129 * 129 as bmp (save as ~49 KB):
http://www.nullskillz.de/terrabrush/terrabrush_seed_hf_129_129.bmp
DL of terrabrush (unfortunately german site):
http://www.cyberfunks.de/page/terrabrush/download.htm