- 日本建築学会計画系論文集 (ISSN:13404210)
- vol.85, no.767, pp.89-99, 2020 (Released:2020-01-30)
The city to create a location optimization plan (LOP) is increasing, with the aim of forming a compact city. LOP should set the Dwelling Attraction Area (DAA) of the residential induction zone, induce residency there, and maintain the population density within the same area as the population of the entire city is reduced. As result of attracting residents and maintaining population density in DAA, outside of the residential induction zone, it becomes an area aimed at reducing the population, and there is a concern about the deterioration of the living environment. In many local medium-sized cities, suburbanization is still underway today. Moreover, there are a lot of cities where suburbs are progressing even if the total population decreases. On the other hand, in suburban areas, which were systematically developed during the rapid population growth period, there is a concern about the rapid increase in the number of vacant lots and vacant houses due to the progression of population decline and aging. Areas urbanized by sprawl, the "circulation of land use" is difficult to generate. In recent years, the occurrence of vacant houses due to the population decline in cities is an urgent issue. Therefore, it is important to understand the status of housing updates in order to consider the planning goals in suburban areas. The purpose of this study is to analyze the changes in urban areas of cities where the population of suburban areas has already be declining, and to obtain knowledge to examine urban area planning goals. As a result, the following points were clarified. In the medium-sized city of 200 to 500 thousand people, there is no city where the population is consolidating between 1995 and 2015. The change in the direction of non-consolidation is a general trend. The difference in the population density of the area where have already urbanized and the suburban area is almost a decreasing trend, and non-consolidation is progressing from this respect. Of these, in Hakodate city where the population decrease in suburban area is the most preceding, the so-called sponge making progresses in the area where have already urbanized. On the other hand, in the suburban area of Hakodate city, the renewal of urban areas and the decrease of vacant lots are progressing even if the population decline continues. In addition, in the four representative districts of the urban area type, the renewal of the house has occurred under the population decrease. At the same time, the vacant house rate has increased significantly over the last 20 years. If there is a re-tenant in the vacant house, the vacant period is about two years. From the above, the following was obtained as a finding to the planning goals of the suburban urban area in the population decrease phase in the medium-sized city. It can be said that it is difficult consolidation to reverse this direction in the tendency of the population distribution change in the urbanization promotion areas is in the suburbanization and leveling. Moreover, the renewal of the urban area in the suburban area is continued even under the population declining from the actual situation of the urban area change in Hakodate city. Even if the house does not change, the resident's replacement continues. Therefore, the sustainability as the residential area is secured without the one-sided vacant lot making and the vacant house progress.