1. School of Environment and Spatial Informatics, China University of Mining & Technology, Xuzhou 221116, China
2. Graduate
School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba,
Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
3. Research Center
for Ecoenvironmental Sciences in Shanxi, Taiyuan 030009, China