Internal Structure of Cities (College Board AP® Human Geography)

Burgess Concentric Zone Model

• The Burgess Concentric Zone Model attempts to explain the different social groups living within urban areas with a circle of concentric rings

  • In this model, the city grows outward from a central area

• The model is comprised of five rings: 

  • The central business district (CBD) is a zone of nonresidential, commercial activities and is characterized by high property costs

  • The zone of transition is characterized by industry and poorer, more-dense housing

    • Historically, immigrant workers lived in this zone

  • The zone of independent workers’ homes, or the working-class residential zone, is populated by working-class families living in older, single-family homes

  • The zone of better residencies is characterized by newer and more spacious homes for middle-class families who can afford daily transportation to the CBD

  • The commuter zone is comprised of suburban residences and populated by people who work in and commute to the city center

Criticisms of Burgess’s model

• The concentric zone model was formulated based on early twentieth-century Chicago

  • As a result, it is not immediately applicable to other cities, particularly in the modern period

  • It does not take into account the effects of:

    • globalization

    • mixed-use urban development

    • decentralization and the growth of edge cities

Image: Rendering of the Burgess Concentric Zone Model, with zones labelled.

Hoyt Sector Model

• The Hoyt Sector Model divides the city into multiple sections based on the sector of economic activity

• The CBD is situated in the center of the model with wedges of different economic activity and types of housing surrounding it

• According to Hoyt, similar activities will remain in one area

  • For example, industrial production relies on many of the same inputs, regardless of the specific item being produced

  • Therefore, industries will all be found in the same sector

  • This sector, according to Hoyt’s analysis, will be along transportation lines, such as railroads to facilitate trade and production

• In Hoyt’s model, low-class residential housing exists alongside the industrial corridor

  • Working-class population would need easy access to industrial jobs

  • Middle and upper-class residential areas would be increasingly further from the industrial sector, but still maintain access to the CBD

• As growth occurs, similar activities remain in the same area and extend outward

Criticisms of Hoyt’s model

• Hoyt’s model is based on the presence of rail transportation, which is now outdated

• It does not consider the existence of personal cars that allow people to commute from low-cost land outside the city boundaries

• It does not take into account the new concepts of edge cities and the fact that CBDs have lost some of their importance as many businesses have moved to the suburbs 

Image: The Hoyt Sector Model, with zones labeled

Harris and Ullman Multiple Nuclei Model

• The Harris and Ullman Multiple Nuclei Model proposes that cities have more than one center around which economic activities revolve

• These nodes include things such as:

  • airports

  • seaports

  • universities

• Certain nodes attract certain specific populations

  • For example, students will tend to live near a university

• In the Harris and Ullman model, CBDs are less important than in the Burgess and Hoyt models

  • The CBD is effectively separated into several nodes, with transportation hubs near industries and airports

  • Low-income housing is situated near manufacturing and shipping areas, while higher-income housing is found in outlying districts

  • Los Angeles is an example of a multiple nuclei city, as it has different centers including a seaport, an international airport, several universities, a CBD, and movie production facilities

    • Each of these is in a different part of the city

Image: The Harris and Ullman Multiple Nuclei Model, with zones labeled.

Galactic City Model

• The Galactic City Model further deemphasizes the CBD and focuses attention on suburbs and edge cities

  • It is used as a model for post-industrial cities

• The galactic model consists of:

  • a central city, surrounded by large suburban residential and business areas that are connected by transportation nodes

  • industry moving to the edge of the city, rather than in the center as in the Hoyt and Burgess models

Image: The Galactic City Model, with zones labeled.

• Other city models to know include the Latin American City Model, the Sub-Saharan African City Model, and the Southeast Asian City Model

Latin American city model

• The Latin American city model includes a thriving CBD with a pronounced commercial spine

• The model takes account of high urban growth rates which result in squatter settlements

• The level of housing decreases as you move outward on the model. The Latin American city model includes seven sectors:

  • The first zone is commercial and runs from the CBD down the commercial spine

    • The CBD employment, entertainment, and the economy

  • The elite residential sector forms on either side of the commercial spine and contains special amenities for the wealthy

  • The middle-class residential sector forms on either side of the elite residential sector, but further from the commercial spine

  • The fourth zone is a mix of middle- and low-income housing, often described as a transitional area

  • The zone of maturity is a residential area with a stable population that has added municipal services

    • It tends to have more middle-class families than the fourth zone

  • The gentrification area is in the process of being converted from low-income renter occupied land to a predominately middle- and upper-class owner-occupied area

  • The last zone is the zone of peripheral squatter settlements, which do not have stable housing or access to most municipal services, such as sanitation or running water

• The Latin American city model can be most easily identified by the presence of the commercial spine

Image: The Latin American City Model

Sub-Saharan African City Model

• The Sub-Saharan African City Model includes three CBDs: 

  • a colonial CBD: characterized by vertical development, including multi-story buildings

  • a traditional CBD: a zone of single-story buildings

  • a market CBD: an open-air, informal trading area

• The quality of housing becomes poorer the farther it is from a CBD

• The presence of minority ethnic neighborhoods persists in the African city model, largely the result of the process of colonization

• Major transportation corridors connect the CBDs to workers living on the outskirts of the city nearest to the mining and manufacturing sectors

  • These sectors are surrounded by squatter settlements

Image: Sub-Saharan African City Model, including labeling of zones and transport corridors.

Southeast Asian city mode

• The Southeast Asian city model aims to present the similarities found in the spatial layout of many cities in Southeast Asia

• The model includes an old colonial port zone surrounded by a commercial business district

• There is no formal CBD in this model. Instead, the different functions of a traditional CBD, including trade, industrial production, and housing, are disaggregated to different sectors of the model

  • New industries are located on the outskirts of the city

• The Southeast Asian city model can be easily identified by the inclusion of the port zone

Image: The Southeast Asian city model, including labeling of zones.

Bid-Rent Theory

• The Bid-Rent Theory suggests that the price of land increases the closer you get to the CBD

• Under this theory, land value increases as density increases and as supply decreases

  • Land closest to the city center, which has the highest population density, will be the most valuable

  • Land further from the city center, with lower population density, will cost less

• Under this theory:

  • commercial businesses will occupy most land closest to the city center

  • industry, which requires more land, will be further from the city center

  • the price of residential property will also be higher closer to the CBD, where more people are “bidding” for scarce land, than further from the city center, where land is more plentiful and cheaper per unit of land

Image: Bid-Rent Curve, illustrating increased price per unit of land closer to the CBD.