1. School of Computer Science, China University of Geosciences, Wuhan 430074, China
2. Hubei Key Laboratory of Intelligent Geo-Information Processing, China University of Geosciences, Wuhan 430074, China
3. School of Economics and Management, China University of Geosciences, Wuhan 430074, China
4. College of Engineering, Mathematics, and Physical Sciences, University of Exeter, EX4 4QF, Exeter, UK