For landscape work I would clearly recommend Nikon or Pentax DSLRs since they offer a significantly superior sensor in terms of dynamic range and a bit more resolution as well (although this aspect is less relevant) compared to Canon's current offerings.
Pentax DSLR have the advantage of a great weather treatment at a reasonnable price. I don't have first hand experience with these bodies, but the K30 is well within your budget. You may want to stretch it a bit and consider a K5IIs with a kit lens though. It should be close to your budget and a great answer to your needs.
Now, Nikon and Canon do offer a more comprehensive lens line up for APS sensors, but that will not be an immediate concern for you considering your budget.
Now, you need to be aware that other formats, based on smaller sensors, are now becoming increasingly more popular because cameras are smaller. The Olympus OM-D would be an interesting option (weather proofed, very good image quality, albeit not as good as the Pentax K5IIs), but it is even more above your budget.