1. School of Geology and Environment,Xi’an University of Science and Technology, Xi’an 710054, China
2. Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, Ministry of Natural Resources, Xi’an 710021, China
3. Institute of Water Resources and Hydro-Electric Engineering, Xi’an University of Technology, Xi’an 710048, China
4. Hebei Geo- Environment Monitoring, Shijiazhuang 050021, China
5. China University of Mining and Technology, Beijing 100083, China