1. Key Laboratory of Virtual Geographic Environment of Ministry of Education, Nanjing Normal University, Nanjing, People’s Republic of China
2. Jiangsu Centre for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, People’s Republic of China
3. School of Geography, Nanjing Normal University, Nanjing, People’s Republic of China
4. School of Earth Sciences, Zhejiang University, Hangzhou, People’s Republic of China
5. Jiangsu Second Normal University, Nanjing, People’s Republic of China