Here is a revised version. I adjusted the shadows on the taller buildings which are the towers of the unfinished wall and changed the river colour. It really didn't come out as planned so I will probably have to do a rethink of that.
I also brought up the contours some more but increasing the strength of the bump mapping in Gimp, to give a better impression of what I'm trying to achieve with the background, which is a surface texture together with a bitmap heightfield generated using mojoworld.
Thanks for all the advice and assistance.
Torq