1. College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
2. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
3. Key Laboratory of Karst Dynamics, Ministry of Land and Resources, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China
4. International Research Center on Karst under the Auspices of United Nations Educational, Scientific and Cultural Organization, Guilin 541004, China