Wow, great first map! Well done!

I like the textures, there is maybe slightly too much contrast between the light areas and the dark areas for me but that's just personal preference rather than anything else.

You do need to have a look at some of your rivers though, there are a few river splits. Rivers normally converge rather than split and where they do split they normally very quickly come back together again. In areas of reliable flooding (or semi-reliable) you might see a river split and converge many times during the non-flooded times but the splits will tend to be confined to the flooded width of the river i.e. along the river bed.

It's still a cracking map and a very impressive work