[1] Beijing Univ, Minist Educ, Dept Urban & Environm Sci, Beijing 100871, Peoples R China
[2] Beijing Univ, Minist Educ, Key Lab Earth Surface Proc, Beijing 100871, Peoples R China
[3] Minist Nat Resources, Ontario Forest Res Inst, Sault Ste Marie, ON P6A 2E5, Canada
[4] Univ Missouri, Dept Geosci, Kansas City, MO 64110 USA