Density of districts of Tokyo-to (Islands excluded) , based on Tokyo map from wikipedia by
利用者:Lincun, Krisgrotius. Data from Tokyo Metropolitan Government: Tokyo Statistical Yearbook, here. Persons/Km2, colour scale based on logarithmic plot. SVG file available upon request, Creative Commons 3.0 etc.
This post is not really about infrastructure, the series will continue but today I present some maps instead.
The population in the mountains decreases and the population close to the centre decreases, especially in Chiyoda-ku which is becomes emptier and emptier. But this doesn't show the whole truth. This is only where people are registered as living, not where they are. During the day the trends turns. The daytime "population" of Chiyoda-ku increases with 800 000 persons. The density increases from 3957 persons to 73315 per km2.
Below are details for some areas. What is notable is the impact of the second world war in redefining the city forever. The population of Bunkyo for example decrease with 2/3 and never recovers when the city is rebuilt, a large part due to the amount of destruction caused by the fire bombings. The economic growth in the 60s stop the people moving back to their old neighbourhood, first some years after the bubble the inner city population starts to grow again. Contrast this with Setagaya-ku where the growth is only weakly affected by the war. Or Tachikawa-shi where the population growth increases when the war starts. Of course this shift from inner city to suburbs and the metropolitan area would have happened without the war, but the change would have been different, slower.
On the other hand, the great Kanto Earthquake in 1923 doesn't seems to have affected the city at all in this data, but there may be many reasons for this.
|Bunkyo-ku, a district inside the Yamanote.|
|Setagaya-ku, a district outside Yamanote.|
|Tachikawa-shi, located far out on the Chuo line.|
For further reading about the development of the Tokyo see: The Making of Urban Japan by André Sorenssen. A book I can highly recommend if you want to know more.