1. Associate Professor, School of Architecture, Harbin Institute of Technology, Harbin 150001, China; Visiting Scholar, Dept. of Geography and Earth Sciences, Univ. of Louisville, Louisville, KY 40292 (corresponding author).
2. Professor, School of Geographical Sciences, Northeast Normal Univ., Changchun 130024, China.
3. Associate Professor, School of Geographical Sciences, Northeast Normal Univ., Changchun 130024, China.
4. Associate Professor, Dept. of Geography and Geosciences, Univ. of Louisville, Louisville, KY 40292.