[1] NW A&F Univ, Chinese Acad Sci, Res Ctr Soil & Water Conservat & Ecol Environm, Shaanxi 712100, Peoples R China
[2] NW A&F Univ, Minist Educ, Shaanxi 712100, Peoples R China
[3] Guangzhou Univ, Sch Geog Sci, Guangzhou 510405, Peoples R China
[4] Calif State Univ Los Angeles, Dept Geog & Urban Anal, Los Angeles, CA 90032 USA
[5] USDA ARS, Natl Sedimentat Lab, Oxford, MS 38655 USA
[6] Jimei Univ, Sch Sci, Xiamen 361021, Peoples R China