*cracks knuckles*
Overall, this looks really awesome! I've been itching to write a constructive review for a while, so please excuse if this comes off as un-needed or pretentious in any way. Just trying to offer some helpful insights and refine my critique process.
Perspective - The horizon doesn't quite line up straight across the picture, but that could be because of an un-even terrain, so not a huge deal.
Foreshortening - Seems stunningly accurate. Every feature looks perfectly sized, and nothing looks too big or too small in relation to its placement.
Outfit / Character Design - Pretty neat since you were going for a futuristic military outfit. It compliments her nicely. Maybe needs a little more protective equipment, though? Not sure what I'm saying, but when I picture a 'military' outfit, I think of a plethora of tools and equipment to fend off threats and potential combat. At least an arrow quiver?
Composition - Nicely centered - can't say anything negative about your choices.
Light Source - Her hair is the only thing that is bugging me. It should be backed in a bright outline, because the sunset it directly behind her. Technically speaking, it would probably be blocking any sunlight from reaching her face, too.
Background - I really appreciate that you put so much detail into the background. Most people just cheap out and do something thought-less or simple. Kudos for making it interact with your character!