Dengfeng Liu, Xi'an University of Technology, School of Water Resources and Hydropower, Xi'an, China, Fuqiang Tian, Tsinghua University, Beijing, China, Hong-Yi Li, University of Houston, Houston, TX, United States, Hui Lu, Department of Earth System Science, Tsinghua University, Beijing, China, Mu Lin, Central University of Finance and Economics, School of Statistics and Mathematics, Beijing, China and Murugesu Sivapalan, University of Illinois, Urbana-Champaign, Urbana-Champaign, IL, United States