1. College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China
2. Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University, Xianyang 712100, China
3. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Xianyang 712100, China