1. Institute of Global Environmental Change, Xi’an Jiaotong University, Xi’an 710049, China
2. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
3. CAS Center for Excellence in Quaternary Science and Global Change, Xi’an 710061, China
4. School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an 710049, China