David Maisel has done some amazing work with aerial photography (a form of landscape in a way!) in addition to the rest of his work which is worth checking out.

If you don't mind crossing to the DPUG, the work of Isabelle Hayeur, her series Excavations in particular, is really worth checking. You can find some images online.

If you want to go really off the beaten track, look for a copy of Jeff Wall's "Landscape Manual" via your university or local library (you'll need to inter-library loan it). It's rather old (1970), but as far as radical looks at landscape go, it takes the biscuit.