Geometrical aspects of intra-urban migration: Migration career and the concept of "spatial configuration"

Abstract

This paper focuses on the geometrical aspects of intra-urban migration in order to reveal the relationship between residential mobility and urban space. Data on Australian migration careers in Adelaide are used. I propose a method to compare the observed migrations and random migrations in order to recognize the regional and behavioral characteristics of intra-urban migrations. Random migrations obtained by computer simulation determine a "spatial configuration" depending on geometry of study areas. For both distance and direction, measures of the differences between the observed and the possible frequency distributions are introduced. Using these procedures and indices, the spatial patterns of the migrations throughout the whole lives of subjects and those at certain life stages are analyzed. The results show that data from Adelaide has distance bias compared with data from two American cities (Santa Barbara, CA and Lexington, KY), that is, short distance migrations are dominant in Adelaide, although there is no significant directional bias. Examination of residential shifts at house purchase does not always conform to the general picture of outward migrations linked to the progress of family life stages and sectoral bias in intra-urban migrations. Movements from first to present residences have clear bias with respect to distance and direction, and this observation indicates that successive migrations do not always take people farther from their first place of residence. This analysis, based on personal migration-career data and simulation procedures, provides some important foundations for comparative studies among cities and for new urban spatial modeling.