著者

石原 健司 小松 幸夫

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

no.769, pp.679-688, 2020-03

被引用文献数

2

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<p> In this study, we analyzed the transition of building stock in the Tokyo wards and visualized the results. The data we used are the GIS databases created by Tokyo Metropolis, which correspond to six time points every five years from 1991 to 2016, and the analysis proceeded as follows.</p><p> 1) Data screening: In order to analyze the GIS data across the years, data screening is needed. We unified the definitions of attribute data and excluded data with missing values and outliers. In addition, since it was confirmed that some divided polygons were contained in the data, then we combined them into the ordinary forms.</p><p> 2) Basic statistics: During the 25 years, the gross floor area has increased by 60% against the 8% increase in the number of buildings, and the average size of the buildings has increased by 48%. However, as for the median, the increase is only 14%. The other quantiles did not change significantly compared to the average value. This may be resulted from the hugeness of some new buildings and indicates that the unevenness of building scale distribution in urban has increased year by year. Also, looking at this from the view of use, the commercial buildings have a strong trend to be large scale, as well as the offices and the apartment houses, while the average gross floor area of detached houses is almost constant. Also, the distribution of gross floor area of detached houses is found out to be converging on around 138 square meters (that is calculated from polygon data and is different from the exact floor area). The changing trends of building size were different depending on the building use.</p><p> 3) Comprehension of building state changes: In order to comprehend the change of the state of a building, the GIS data of 2010 and 2016 were spatially overlapped and the identification of buildings were implemented, then we extracted the buildings seemed to be not same as before. As the result of overlapping, the change patterns of building state were classified into six types, as "Rebuilding", "New Construction", "Demolition", "Integration", "Division", and "Other". Comparing the change of building size by patterns, there was a remarkable trend of enlargement in "Integration" and miniaturization in "Division". "Integration" shows higher proportion than other patterns in the commercial buildings, the offices and the apartment houses. On the other hand, most of the "Division" was occurred in the detached houses. It is considered that these results are related to the transition of the total floor area of each building use.</p><p> Looking at the geographical distribution density of building change patterns using kernel density estimation, the "Demolition" and the "Integration" had high density mainly in the downtown area, and the "Division" was distributed mainly in the residential area. In addition, the "New Construction" occurred at the outer edge. The huge buildings are thought to appear caused by the "Demolition" and the "Integration" around the center area of the city. In addition, it is also suggested that the living environments are changing as "Divisions" are actively carried out in old residence towns.</p>