sustainability Article Examining the Density and Diversity of Human Activity in the Built Environment: The Case of the Pearl River Delta, China Miaoxi Zhao 1,*, Gaofeng Xu 2, Martin de Jong 3, Xinjian Li 4 and Pingcheng Zhang 5 1 Department of Urban Planning & State Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640, China 2 Department of Urban Planning, Tsinghua University, Beijing 100084, China;
[email protected] 3 Erasmus School of Law & Rotterdam School of Management, Erasmus University Rotterdam, Postbus 1738, 3000 DR, Rotterdam, The Netherlands;
[email protected] 4 School of Civil and Mechanical Engineering, Curtin University, Perth, WA 6907, Australia;
[email protected] 5 Department of Computing, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong, China;
[email protected] * Correspondence:
[email protected]; Tel.: +86-138-2602-5180 Received: 2 March 2020; Accepted: 27 April 2020; Published: 3 May 2020 Abstract: Rapid urbanization in China has been accompanied by spatial inefficiency in patterns of human activity, of which ‘ghost towns’ are the most visible result. In this study, we measure the density and diversity of human activity in the built environment and relate this to various explanatory factors. Using the Pearl River Delta (PRD) as an empirical case, our research demonstrates the distribution of human activity by multi-source data and then explores its dynamics within these areas. This empirical study is comprised of two parts. The first part explores location information regarding human activity in urbanized areas and shows density and diversity.