1. Lecturer, School of Architectural and Surveying and Mapping Engineering, Jiangxi Univ. of Science and Technology, Ganzhou 341000, China.
2. Professor, School of Environment Science and Spatial Informatics, China Univ. of Mining and Technology, Xuzhou 221116, China (corresponding author).
3. Lecturer, School of Environment Science and Spatial Informatics, China Univ. of Mining and Technology, Xuzhou 221116, China.