1. Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
2. Institute of Atmospheric Sciences, Jiangsu Academy of Environmental Sciences, Nanjing, 210036, China
3. Institute of Population Research, Peking University, Beijing 100871, China
4. College of Resources and Environment, Shanxi Agricultural University, Shanxi, 030800, China