La mobilité résidentielle intra-urbaine au Havre et à Rouen

Résumé En

Intra-urban residential migrations in le Havre and Rouen, Among the 49.650.000 inhabitants living within the French boundaries in 1968 and considering the number of deaths which occurred in the meantime, a little more than 21 million inhabitants (i.e. 42.5 % out of the total population) were no longer living in the same place in 1975. The study of migration levels between communes reveals that only 13 million have moved to another commune and that out of this number 3.7 million have moved within the same urban area: therfore, during these 7 years, 8 million (i.e. more than 16 % of the 1968 census) have moved within the commune where they had been registered at the beginning of the inter-censal period. In the very communes belonging to urban areas which count more than 100.000 inhabitants this proportion nearly reaches 20 % of the 1968 census that is to say 40 % of the national migration. A percentage which should not be underestimated as far as residential migrations are concerned; now, before the study of the 1975 census covering the 1968-1975 period, it was almost impossible — at least in France — to analyse these migrations always excepting inquiries which were inevitably punctual or the studying of non-specific data. This period was the first one which it became possible to measure these migrations thoroughly; indeed it shows that in the city of Le Havre more than 30 % of the 1968 residents have moved within the limits of the same commune when less than 50 % had not moved at all, seven years later. For the 1975-1982 period, the proportion of intra-urban residential migrants falls slightly, but hardly more than 40 % have not moved at all. For either one of these inter-censal periods, intra-urban migrations have altered the population of the neighbourhoods much more than extra-urban migrations have done it. In Rouen, on account of a different spatial distribution of the urban area and because of its high levels of migration, intra-urban migrations are much more reduced but still, non-migrants are comparatively far less numerous : less than 40 % for the single city of Rouen 43 % for the surrounding communes, between 1968 and 1975. The enumeration of the births which occurred during the inter-censal period — a few of them occurring before the residential migration of the family — the enumeration of the deaths, the reconstitution of the original population: these are some of the restraining statistics which should be overcome at first. Then one should go beyond the literal interpretation of the migration trends, (though it may reveal wide variations) and address to a qualitative study of the migrations: unfortunately when the geographer gets down to the neighbourhoods of the city, the data issued from the census are not easily available which undermines the feasibility of such an inquiry; but still, it would be very interesting to investigate the neighbourhoods where out-migration and in-migration take place so as to determine the role of these migrations upon the observed mutations. Nevertheless, it is possible to determine some of the characteristics of these migrations (their age, their birth and growth rates and when statistics are sufficient, their social status) and to highlight their distinctive features when compared to other categories of migrations. Here we are confronted to an unexplored field of investigation; but still it opens new fields of investigation into the type of residence acquired and into the different processes related to spatial developments in urban areas.