1. Graduate School of Environmental Studies, Nagoya University, D2-1Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
2. Institute of Urban Innovation, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan
3. College of Resources Science and Technology, Beijing Normal University, 19 Xinjiekouwai Street, Beijing 100875, China
4. Department of Geographical Sciences, University of Maryland-College Park, College Park, MD 20742, USA