The evolving metropolis after three decades: a study of community, neighbourhood and street form at the urban edge

摘要

In a highly cited paper, Southworth and Owens (1993) studied eight suburban areas in the San Francisco Bay area at the scales of community, neighbourhood and of street and house lot, and observed their changing morphological characters over time. Using USGS and Google Earth data and census data, a more robust analysis of the same areas was performed to identify changes during the last three decades and to re-test the validity of the authors' original findings. Findings support and amplify previously observed morphological characters. Taken together, they reveal only minor changes to the overall pre-existing morphological patterns. Community street and land use patterns show minor changes but reveal additional complexity. Community urban patterns show densification through small-scale developments. Neighbourhood street patterns reveal previously unidentified differences between and within study areas. New residential developments also reveal previously unidentified types. Despite only minor morphological changes, significant socio-economic changes are observed in the study areas showing improvements in living standards during the study period. These changes are characterized by an increase in per capita income, density and diversity. Therefore, it is concluded that positive socio-economic changes can occur in suburban areas at city edges, even when these areas resist any significant physical changes.