1. Institute of Karst Geology, CAGS/Key Laboratory of Karst Collapse Prevention, CAGS, Guilin, Guangxi 541004, China
2. China University of Geosciences, Beijing 100083, China
3. Zhejiang Engineering Survey and Design Institute Group Co. Ltd., Zhejiang 315012, China
4. Hebei Women’s Vocational College, Shijiazhuang, Hebei 050093, China