1. Department of Geography and Spatial Information Techniques, Ningbo University, Ningbo, China
2. School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
3. Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, China
4. Hubei Key Laboratory of Applied Mathematics, Faculty of Mathematics and Statistics, Hubei University, Wuhan, China
5. Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China