Abstract
The rapid increase in population of the marginal suburbs of Tokyo is one of the most remarkable phenomena in recent years. A great horizontal (not vertical) expansion, by newly constructed houses has been made in the urban margin, which is a characteristic of Japanese city-growth. The result of it was that the City had to enlarge its municipal area in October, last year.
The region under discussion is the area comprised in 12 sheets of the, 1/10, 000 scale maps of the western part of this enlarged city, except the old municipal area. The density is obtained by calculating the percentage of area occupied by houses per 100 metre square. Fig. 5 is an example of iso-density lines.
In reading the density map (Plate I), we know that there are some high density zones which extend to long distances continuously, and that they follow the early laid suburban tram-car lines that skirt the highways, radiating from the city. Along the recently opened lines, only, small isolated towns are seen near certain stations. The N-E and S-E parts of the map are areas crowded with many communication lines and the seats of complicated, high-density population.
We can then classify many house-blocks as in the case of geomorphology with the result shown in Fig. 6. Fig. 7 shows closed form groups of houses, namely, the small business centers.
By field surveying (Fig. 8. 9 and Table. I, II), the author found that areas showing more than 15% of house-density have, in most cases, an urban character, hence the geographical (not political) boundary of the City of Tokyo has complicated outlines, as shown in Fig. 10. There are still same large non-urban areas Within the new municipal limit.
