Speaker
Description
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Introduction
In a society with a declining population, significant changes are required in the large metropolitan areas that have been consistently expanding since the end of the Second World War. Optimizing the scale of conurbations is an urgent issue to ensure that our living environment is safe, secure, and sustainable (Dunham-Jones & Williamson, 2011). In this context, there is much hope for the concept of compact cities, which aims to improve cities' sustainability while coexisting with nature (Aoki, 2023).
However, the discussion of compact cities mainly converges on mono- or poly-centric models (Aoki & Itami, 2024). On the other hand, like Japanese conurbations have structures in which cities are linked along railway lines. Therefore, people's living areas effortlessly straddle multiple municipalities. Another issue is the deterioration of the urban environment due to the random occurrence of underutilized land - the urban perforation- which decrease the attractiveness areas.
Therefore, we should also consider linear compactness theories when discussing compact cities in a society with a declining population. It may also be necessary to make effective use of low-density/underutilized land that has arisen due to urban perforation, which is one form of shrinking cities beyond the boundaries of local governments. -
Methodology
This study takes the Kyoto-Osaka-Kobe conurbation, Japan's second-largest metropolitan area, which is experiencing population decline. Several private railway companies operate in this conurbation, and historically, they have developed suburbs (Kadono 2000).
Firstly, we clarify the spatial distribution of urban perforation in terms of population and building density using the National Census and Building construction data. We estimate the structure of urban perforation using spatial autocorrelation analysis. In addition, we observe the progress of urban perforation using data from multiple years.
Secondly, observation beyond the different urban and railway line structures will deepen the recognition of urban perforation. We classified the area on the objective conurbation into the "single line" and the "multiple parallel lines." In addition, based on their location, each railway line is divided into three types: "inter-central," "suburban," and "branch." -
Findings and Discussion
As a result, it became clear that low-density urbanization does not necessarily occur from the outer edges of the conurbation and each administrative district. Residential and land use along the railway lines is relatively stable, and it is thought that it is not easy to accurately estimate the linear urban structure of the target area using the monocentric or polycentric compact city concept. In particular, although there are low-density areas in the surrounding areas of railway lines that run in parallel, the overall situation is stable. On the other hand, low-density areas are prominent along branch lines, and there is a tendency for residential and land use to be dispersed.
In the context of demographic and land use characteristics, residents' attributes differ from one adjacent station to the next. In addition, there are differences in the rate of accumulation and the types of accumulation in each section along the line. As indicated in the TOD theory, in addition to the accumulation in significant cities and connection by public transport, we should consider a new compact urban structure based on a relationship of mutual support that also encompasses the stations in close proximity to each other. -
Conclusion
The findings of this research have examined the relationship between urban perforation and railway networks in shrinking cities and presented a new way of looking at compact cities. However, as this is a case study of Japan, the possibility of applying it to other conurbations should be considered. In addition, indicators and methods for measuring compactness must be sought in the near future.
References
Aoki, T. (2023) Activity space compactness index from the viewpoint of trip arrival point by lifestyle activity purpose in a mature conurbation, Sustainable Cities and Society, 88, 104302 https://doi.org/10.1016/j.scs.2022.104302
Aoki, T., & Itami, E. (2024) What is the Role of Workplaces Developed Proximity to Suburban Residential Areas for the Future Urban Compactness?, Urban and Regional Planning Review, 11, 1-21 https://doi.org/10.14398/urpr.11.1
Dunham-Jones, E., & Williamson, J. (2011) Retrofitting suburbia. Urban design solutions for redesigning suburbs, Wiley, United States of America
Kadono, Y. (2000) 20 century of suburb, Gakugei publishing, Kyoto (in Japanese)
| Keywords | Compact Cities; Urban Perforation; Shrinking Cities; Linear-based compactness |
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