Thanks, that's very inspirational! The colours of the river and earth are just right.
I cannot take credit for the earth colours, I used the paints suggested by Jeff965 (see post on page 2), but they give nice tones, and I also used a much lighter final dry brush as well as a more yellow ochre in patches to add some variety. A lot of the earth colour is lost when flocking, but at least it is there if the flock comes way.
I used about 8 different grass colours to achieve this look starting with a light green then a golden yellow, following with patches of lighter and darker greens and browns. Finally I dabbed fine flock over the grassed area to give a bit more texture. The sisal/jute liner is very good for representing rougher ground, and it is flat, although you can easily add indentations with your fingers as you glue it to give a more undulating effect. The light greenish colour of this stuff means you do not need to worry too much about a heavy covering of grass, and works well if you want a drier effect.