Simulation of urban perforation after random vacant plot generation: application of the thinning point process

Abstract

The spatial patterns of the generation and accumulation of vacant plots tend to be randomly distributed. This phenomenon, which represents morphological changes in urban areas, is called urban perforation. Urban perforation should be considered when discussing the spatial compaction of existing morphological urban areas; therefore, the morphological changes in urban areas caused by urban perforation must be simulated. However, suitable simulation methods have not been developed. This study applied the thinning point process developed in stochastic geometry to simulate the generation and accumulation of vacant plots and answered the following research questions based on empirical analysis in Sakura, Japan: (1) Can the thinning point process be used to simulate spatially random patterns of vacant plot generation in each built cluster? (2) Will accumulated vacant plots exhibit spatially random patterns in each built cluster after repeating the thinning point process? Evaluations of simulation performance revealed that the thinning point process did not always produce spatially random patterns of vacant plot generation and accumulation; however, the simulated dispersed patterns were logically consistent with urban perforation and revealed fragmented vacant plots. The results of this study may be used to predict future morphological urban areas in an era of urban shrinkage.

Keywords:

• Thinning point process
• vacant plot
• perforation
• urban area
• complete spatial randomness

Acknowledgments

The author is grateful to the editors and anonymous referees for their extremely valuable comments and suggestions. This research was the result of the joint research with CSIS, the University of Tokyo (No. 785) and used the following data: Residential Maps provided by Zenrin, CO., Ltd.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data and codes availability statement

The sample data and codes supporting the findings of this study can be obtained via the following permanent link: https://doi.org/10.6084/m9.figshare.20473656.v1.

Notes

1 Titled the ‘Midterm Summary of the Division of the Subcommittee for City Planning System’ https://www.mlit.go.jp/policy/shingikai/toshi01_sg_000194.html (accessed December 2022).

Additional information

Funding

This research was supported by the Japan Society for the Promotion of Science (20H02383 and 22H00245).

Notes on contributors

Hiroyuki Usui

Hiroyuki Usui received PhD from the University of Tokyo in 2014 and now is an assistant professor of the Department of Urban Engineering, the University of Tokyo. His research interests are city planning, urban morphology and spatial analysis. He published papers in spatial analysis-related journals, such as the International Journal of Geographical Information Science, Environment and Planning B: Urban Analytics and City Science, and Computers, Environment and Urban Systems.