Greetings. For my first contribution to this forum, I am presenting a set of gradients for use in GIMP

gradients.jpg

gradients.zip

These can be used on greyscale heightmaps with the "Gradient Map" option.

On Linux, they can be installed by extracting the contents of the ZIP file into
Code:
/home/<your username>/.config/GIMP/2.10/gradients/
. On Windows, there must be a folder for all the things GIMP has well.