1. Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology , Guangzhou, Guangdong 510006 , P.R. China
2. School of Environment, Beijing Normal University , Beijing 100875 , P.R. China
3. School of Applied Economics, Renmin University of China , Beijing 100872 , P.R. China
4. The Bartlett School of Sustainable Construction, University College London , London WC1E 6BT , UK
5. School of Management, China University of Mining & Technology-Beijing , Beijing 100083 , P.R. China