大都市中心部からの転出人口に関する一考察

名古屋市中区の場合

抄録

Migration is one of the most interesting subjects not only in demography but also in geography. When we consider the origin and destination of migration, we find that urban areas are of great importance. Especially the center of the metropolis has a lot of mobile people and many out-migrants. We can distinguish three typical patterns of migration from the center of the metropolis: decentralization in the metropolitan area, migration to another metropolises and return to their native places. But the intensive studies on intraurban migration, interurban migration and urban to rural migration like a so-called “U-turn” phenomenon have not been done well.
In this article, the writer adopted Naka-ku, the center of the Nagoya metropolis, as a research area. Its objects are 7, 852 out-migrants from Naka-ku in 1972 whose names were struck off a resident registration's list. They are equivalent to about 60% of all the out-migrants from Naka-ku in the year. The data for this study are sex, age (5-year groups), duration of residence, destination and origin (before Naka-ku) of out-migrants, and date and type (personal or family) of out-migration. The objectives of this paper are to recognize the features of out-migrants and migration process and to understand the constitution of migration from the center of the metropolis.
The features of out-migrants shown in tables 3∼4 are summarized as follows.
(1) The mobility of man is higher than that of woman.
(2) Out-migrants consist chiefly of young people from 20 to 34 years old and in case of personal migration this trend is more remarkable.
(3) Generally speaking, the duration of residence is very short, and out-migrants whose duration of residence is less than three years are the greater part of the whole. In case of family migration it is pretty longer than in case of personal migration. And the longer the duration of residence is, the larger the family is.
Then the features of out-migrants viewed from each destination are shown in tables 5∼7.
(1) Most of out-migrants are short-distance migrants and more than 70% of them moved out to three prefectures of Tokai districts (Aichi, Gifu, and Mie Prefectures). Applicating the gravity model to the relation between distance and the number of migrants, the restriction of distance is comparably weak.
(2) In case of family migration, short-distance and interurban migrations are more frequent than in case of personal migration. The longer the distance is, the smaller the family is and, at the same time, the shorter the duration of residence is.
(3) In case of personal migration, the longer the distance is, the greater the number of young people is and the shorter the duration of residence is.
By the way, it is one of the most important subjects in this study to analyze the migration process. The results viewed through the analysis of the relation between the destination and the origin of out-migrants are as follows.
(1) There are many out-migrants whose destination and origin are entirely the same or near areas. About half of the long-distance migrants are recognized as so-called “U-turn” migrants who came to metropolitan areas from rural areas for working or studying and returned to the same or near areas for working. Therefore we can identify the existence of a so-called “U-turn” phenomenon.
(2) “U-turn” migrants are mainly composed of young people from 15 to 29 years old whose duration of residence is very short.
(3) In case of intraurban migration, there are also many out-migrants whose destination and origin are the same or neighboring places (ku). The ratio of outmigrants, who moved out for the first time, to intraurban out-migrants is a little high and their mobility is not high. Then Intraurban migration patterns are pretty complexed by many factors.