State Key Laboratory of Resources and Environmental Information Systems;
Institute of Geographic Sciences and Natural Resources Research;
Chinese Academy of Sciences;
Beijing 100101;
China;
School of Environmental Science and Engineering;
Tianjin University;
Tianjin 300072;
China;
University of Chinese Academy of Sciences;
Beijing 100049;
China;
College of Urban and Environ-mental Science;
Liaoning Normal University;
Dalian 116029;
China;
School of Soil and Water Conservation;
Beijing Forestry University;
Beijing 100083;
China;
College of Urban and Environmental Sciences;
Central China Normal University;
Wuhan 430079;
China;
Geography Department College of Sciences;
Yanbian University;
Yanji 133002;
China;