Distribution of Urban Population in the Tokyo and Osaka Metropolitan Areas, 1883-1985

Retrospective estimates of urban population distribution in the Tokyo and Osaka (or Keihanshin, i.e. Kyoto-Osaka-Kobe) Metropolitan Areas have been made to reconstruct the historical processes of urbanization, dating back to 1960, 1935, 1908 and 1883. A method has been explored by the author to estimate micro-scale distribution of population by standard mesh comparable with the published mesh data, which have been available since 1970. Outline of the method to estimate distribution in 1960 is as follows: 1. Meshes both in 1960 and 1970 are delimited according to the borders of local government areas (LGAs) or equivalent small areas in 1960. 2. The meshes in 1960 within each LGA are classified into three categories, i.e. DID meshes, stable meshes and growing meshes, through comparisons of topographical maps and other various sources. DID meshes represent the DIDs (Densely Inhabited Districts, defined and published since 1960); stable meshes are mainly those of rural nature with minor changes, and population can be relatively easily estimated; and growing meshes are those with rapid population growth mainly caused by urbanization, and population in 1960 is estimated as the remainder by deducting populations of the other two categories from total population of the LGA. 3. Population in each category is allocated among the meshes according to the known distribution in 1970, assuming that relative distribution among the meshes within each category would not be so much different between the two dates. Population distribution for the earlier dates can be estimated in almost the same way, except the lack of DID data: this defect is partly compensated by smaller size of LGA with relatively clear distinction between urban and rural LGAs, and also partly by more precise estimates of growing meshes, mainly through comparisons of landscape features on the topographical maps with similar ones in 1960 or 1970, for which population data are already available. The results are summarized in Tables 1-3 and Figures 1-6. A mesh with population over 2,000 is operationally defined as urban, based on the comparison between the mesh data and the DID data in 1985. Major findings are as follows. 1. Urban population in the Osaka M.A. have failed to catch up with the Tokyo M.A. after 1935, although the former was almost comparable to the latter before 1935 (Tables 1 and 3). 2. One of the common features is that urban population and area (number of meshes) in both areas expanded around major centres (Tables 1-2 and Figures 1-3 and 6), showing concentric patterns with growing and expanding outer areas in contrast to declining inner areas from the earlier periods (Figures 4-5), partly reflecting the changing urban transport system from trains to suburban railways as well as motorization. 3. Urban areas in both areas have expanded more rapidly than urban population, resulting in declining average density after 1908 or 1935 (Table 2), as well as decreasing percentage in high density meshes over 16,000 (Table 2 and Figures 1-3). And also, meshes with rapid apparent inflow over 8,000 (including additional natural increase by migrants) have been giving way to those with slower apparent inflow (Table 3 and Figures 4-5). Although the spatial expansion with declining density may be interpreted to reflect improvement of living environment, we should not neglect that it has also affected the overall land use by taking over more farmlands and woodlands