1. College
of Tourism, Huaqiao University, Quanzhou, Fujian 362021, China
2. Key
Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
3. Department
of Geological and Mining Engineering and Sciences, Michigan Technological University, Houghton, Michigan 49931, United States
4. Department
of Civil and Environmental Engineering, Michigan Technological University, Houghton, Michigan 49931, United States