1. Agricultural Information Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
2. College of Agronomy, Inner Mongolia Agricultural University, Hohhot 010019, China
3. Institute of Environment and Sustainable Development, Agricuture of Chinese Academy of Agricultural Sciences, Beijing 100081, China
4. Jiangsu Center for Collaborative Innovation, Geographical Information Resource Development and Application, Nanjing 210023, China
5. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
6. School of Surveying and Geo-Informatics, Shandong Jianzhu University, Jinan 250101, China