1. National Engineering Research Center of Coal Mine Water Hazard Controlling; China University of Mining & Technology, Beijing, No. Ding 11 Xueyuan Road, Haidian District; 100083 Beijing China
2. Illinois State Geological Survey, Prairie Research Institute; University of Illinois at Urbana-Champaign; Champaign IL 61820
3. Information Engineering College; Beijing Institute of Petrochemical Technology, No. 19 Qingyuan Road, Daxing District; 102617 Beijing China
4. College of Science; China University of Mining & Technology, No. Ding 11 Xueyuan Road, Haidian District; 100083 Beijing China