1. College of Resources and EnvironmentNorthwest A&F University Yangling City Shaanxi Province China
2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess PlateauNorthwest A&F University Yangling City Shaanxi Province China
3. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess PlateauInstitute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources Yangling Shaanxi China