[1] China Univ Mining & Technol, Sch Environm Sci & Spatial Informat, Xuzhou 221116, Peoples R China
[2] Anhui Prov Inst Land Surveying & Planning, Hefei 230631, Anhui, Peoples R China
[3] Vrije Univ Brussel, Dept Geog, Earth Syst Sci, B-1050 Brussels, Belgium
[4] Anhui Jianzhu Univ, Sch Environm & Energy Engn, Hefei 230601, Anhui, Peoples R China