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Models of Urban Structure:

Accessibility and Land Use:

isotropic surface: a hypothetical, uniform plain: flat, and with no variations in its physical attributes. Where would the following businesses be located:

grocery store, R.V. dealer, Lawyer's Office

urban form:
the physical structure and organization of cities.

Compare the street pattern of the old city on page 458 with the streets of a typical American city. What accounts for the difference?

central cities: the original, core jurisdictions of metropolitan areas.

isochron: a line connecting points of similar time (distance traveled in a given time) determining the radius of the city.
Innovations in transportation extend the isochron of commuting distance - thus allowing the city to sprawl.

Temporal Urban Mapping - (mirror site in France) - Animation of urban growth for the San Francisco Bay Area and of Washington D.C.

sprawl: a term, often used pejoratively, describing the unplanned extension of relatively low-density urban land uses into rural areas, usually alongside main roads. Sprawl implies little control of land subdivision, so that the conversion of plots for urban uses may create enclaves of agricultural land . . . (RJ. Johnston Dictionary of Human Geography Blackwell Press 2000).

edge cities: nodal concentrations of shopping and office space that are situated on the
outer fringes of metropolitan areas, typically near major highway intersections.

fiscal squeeze: increasing limitations on city revenues, combined with increasing
demands for expenditure.

hinterland: the sphere of economic influence of a city or town. The resource area of a city.

Social and ethnic clustering/social ecology - people congregate or discriminate resulting in segregation.


central business district (CBD): central nucleus of commercial land uses in a city.

zone in transition: area of mixed commercial and residential uses surrounding the

invasion and succession: a process of neighborhood change whereby one social or
ethnic group succeeds another.

minority groups: population subgroups that are seen, or that see themselves, as
somehow different from the general population.

congregation: the territorial and residential clustering of specific groups or sub-groups
of people.

redlining: the practice whereby lending institutions delimit "bad risk" neighborhoods on
a city map and then use the map as the basis for determining loans.

segregation: the spatial separation of specific population subgroups within a wider

underclass: subset of the poor isolated from mainstream values and the formal labor

cycle of poverty: transmission of poverty and deprivation from one generation to
another through a combination of domestic circumstances and local, neighborhood

gentrification: the invasion of older, centrally located working-class neighborhoods by
higher-income households seeking the character and convenience of less expensive
and well-located residences.

Functional clustering/Multiple Nuclei - some activities attract or repel each other.

Corridors and Sectors Model - neighborhoods develop in response to transportation routes and topography.

Illustrated on p.445 of your textbook.

Additional Resources:

Urban Geography Links