Urban transformation and population decline in old New Towns in the Osaka Metropolitan Area

In shrinking cities, old New-Towns have emerged as an urban issue in recent years as the population ages. New-Towns were quiet residential areas that flourished as neighborhoods that provided housing during the population boom from 1960 to 1990. New-Towns were developed on the design principle of Perry's neighborhood unit model. However, New-Towns have become "old New-Towns" with many older adults. The aim of this study is to examine the nonlinear relationship between population decline and urban transformation by using the urban transformation of houses in old New-Towns. This study analyzed the Osaka metropolitan area as a case study. The XGBoost algorithm was used to analyze the nonlinear relationship between urban transformation and population change. In conclusion, population decline correlates with the urban transformation of houses into health care facilities in old New-Towns in Japan. This means that the neighborhood unit model, which focuses on children, has changed to one that focuses on older adults. However, there have been fewer old NTs that transformed from housing to health care facilities than changes to other land uses. Therefore, urban planners need to develop policies to encourage the construction of health care facilities and mixed land use in old New-Towns.