I'm using Corel X5 for this. Some things look strange so I put labels on it to show what I'm going for. The southeast has been over-mined (ore veins close to the surface). There are man-made canals and water bodies used as fisheries and breeding pens. The northeast mountain range is magically created to block the lava. It drew the nutrients from the surrounding land creating the desert. Any criticism is welcome.:)
You've got some river divergence issues that don't appear to be the canals you mentioned. Rivers don't split other than very briefly (Forming a fluvial island, which doesn't last very long geologically speaking) or in deltas at their mouths.
Also, Corel what? Draw, Photo-Paint, Painter, Paint Shop Pro? Corel makes a lot of graphics software.
I like the overall design ! :)