Urban Interior Boundaries Delimitation Respecting to Human Mobility

Administrative divisions are regional divisions of the state for the purpose of hierarchical administration. With the development of urbanization process, a concern arising from the changing urban dynamics is that whether current administrative division accords with urban development? Following the concept of urban space formed by human activities, existing studies have sought proxies for human activities and then delineated urban boundaries formed by human activities from a data-driven perspective. However, their lack of exploration into the implicit human activity patterns behind the proxies results in weak interpretability and rationality of methods and results. This paper studies the delineation of urban interior boundaries respecting to human mobility patterns. Specifically, this paper first uses human mobility as a proxy to construct a network that represents spatial interaction in urban regions. Then we explore the region-based human crowd mobility patterns to reveal the mechanisms behind the formation of urban space through human activities. Finally, we employ the community detection technology to naturally delimit the urban interior boundaries formed by human mobility, and make a comparison with the official urban boundaries. Taking Xi'an in Shaanxi Province of China as an example, we conduct the delineation on the spatial interaction network based on the real mobility information of 24,770,715 mobile phone users in the whole city. We find that human mobility can establish a stable correlation between regions (or capture the objective correlations between regions), and the human crowd patterns are applicable for mining unusual urban regions from the perspective of anomaly detection, which are of great significance for understanding the urban spatial structure based on empirical evidence. In addition, in the final delineation result, some unexpected communities that are closely linked due to human activities appear from the results, and these findings help the urban planners re-examine the administrative division.