Abstract
1. Tomeihan District here means the district which extends along the Tokaido Line and contains Keihin, Chukyo and Keihanshin metropolitan regions.
2. Population concentration ratio (P. C. R.) is defined as the percentage of the social change of population to the total population in a given area.
3. The distribution of the P. C. R. in Tomeihan District denotes that:
(a) The P. C. R. in the areas containing the civic centers of Tôkyo, Yokohama, Nagoya, Kyôto, Osaka, and Kôbe are minus as the results of the decentralization of population and the ratios are higher in proportion to the scale of the cities.
(b) the statistical number of population in the surroundings of the civic centers abovevand in the cities of the remote areas from large cities are plus, but if the social increase is taken into consideration, they denote minus as there are out-migrations from these cities.
(c) the P. C. R. in the outer fringes of the built-up areas of Keihin, Nagoya and Osaka are very high with the concentration of population from the inner areas of every city and from all over the country.
4. The increase rate of population in Tôkyo region is the highest compared with those of Osaka and Nagoya and the concentrated population in Tôkyo region permeates not only into the Densely Inhabited Districts (D. I. D. s), but also into the areas outside the D. I. D. s.
5. In Tôkyo region, there are extensive uplands which are convenient for the recent housing development and the industrialization as Musashino, Shimôsa, Omiya, etc. On the contrary, there are not such extensive uplands in Osaka region and there extend low paddy fields in the surroundings of the builtup areas of Osaka. These differences in the topographical conditions influence the recent urbanization of every region.
6. With the data concerning the commuters, the author calculated the out-commuters ratio and the in-commuters ratio by ski, cho, son. The region where housing developments have been recently rapid, the out-commuters ratios are higher and inversely in the region where the industrialization has been rapid, the in-commuter ratios are higher. By the distribution of these ratios, the differences of urbanization in the fringing areas of the metropolitan regions can be known.
