The trend of multinucleation and the characteristics of suburban nucleations in the Keihanshin metropolitan area

Abstract

This paper aims to examine how multinucleation is currently progressing and what characteristics of nucleations are found in the Keihanshin metropolitan area. For an analysis of this study, the author made full use of the data obtained by "The Person Trip OD Survey in the Keihanshin Metropolitan Area in 1990." This survey divided the Keihanshin metropolitan area into 855 zones and provided with data on the movement of inhabitants across those zones and their socioeconomic attributes (e. g., age, gender, occupation and so on). First, the author selected nucleations of working activities and of consuming activities on the basis of what extent inflow trips exceed outflow trips across zones in case of either commuting (as "a nucleation of working activities") or purchase and leisure (as "a nucleation of consuming activities"). Thus 44 CBD zones, 30 inner city zones and 35 suburban zones were extracted as "nucleations of working activities," and also 12 CBD zones, 11 inner city zones and 37 suburban zones were extracted as "nucleations of consuming activities." While only a small number of "suburban nucleations of working activities" are extracted they are smaller in size than those in the CBD, a large number of "suburban nucleations of consuming activities" are extracted and some of them are found to be as large as those in the CBD zone. Secondly, for the purpose of examining the main functions of each nucleation, the author conducted a cluster analysis by comparing arrival trips to 18 facilities (e.g., housing, offices, retail shops, wholesale shops, factories and so on) in each nucleation, and 9 clusters were extracted. Four of them represent characteristics of the CBD (centrality), and five of them represent characteristics of suburbs. Among the five suburban clusters, two clusters represent characteristics of suburban nucleations. There are many differences between CBD and suburban nucleations, although some suburban nucleations resemble the CBD in functions. Thirdly, the author analyzed the age structure of working women as well as traffic patterns. In the female clerical workers, there was a difference between CBD and suburban nucleations. In suburban nucleations a much higher share in women in their 40s was counted but much lower in their 20s. The same pattern was also found in the female sales workers in the "nucleation of consuming activities." As for women's working structure, some nucleations of working activities and consuming activities resemble the CBD in functions and they all represent characteristics of suburban nucleations except one which is adjacent to Osaka (central city). In traffic patterns, the CBD has a much higher share in railroads, while suburbs have a higher share in automobiles. But suburban nucleations show a higher share in railroads than other suburbs because in many cases the main railroad stations contribute to the development of a suburban nucleation in the early stage of suburbanization. The nucleations of inner city areas show the same pattern as suburban nucleations in terms of function, female working structure and traffic patterns. As a result of this study, it is found that there are many different characteristics between CBD and suburban nucleations. This study has also shown that "the nucleations of consuming activities" are already in the stage where "supplementary multinucleation" has fully developed enough to supplement the function of the CBD, but "the nucleations of working activities" are only in the stage where "supplementary multinucleation" has just started.