[1] Lanzhou Univ, Coll Earth & Environm Sci, Key Lab Western Chinas Environm Syst, Minist Educ, Lanzhou, Peoples R China
[2] Lanzhou Univ, Observat & Res Stn Ecoenvironm Frozen Ground Qilia, Lanzhou, Peoples R China
[3] Texas A&M Univ, Dept Geog, College Stn, TX USA
[4] Qinghai Prov Geol Disaster Prevent & Control Tech, Qinghai Prov Gen Geol & Environm Monitoring Stn, Xining, Peoples R China