Seven Models of Urban Internal Structure

Foundations of Urban Internal Structure

• Cities are primarily composed of three entities: a Central Business District (CBD), industrial or commercial districts, and residential locations.

• Bid Rent Theory: Land is most expensive within the CBD and progressively decreases in cost as distance from the center increases.

• Understanding these models requires analyzing strengths, limitations, transportation innovations, and the relationships between sectors.

Burgess Concentric Zone Model ($1920s$)

• Origins: Developed by Burgess based on studies of Chicago during the $1920s$.

• Structure: The city identifies as a series of uniform concentric circles radiating from the CBD.

• Zones:   * Circle $1$: CBD and transportation hub.   * Circle $2$: Zone of transition (industrial/low-cost housing).   * Circle $3$: Working-class residential.   * Circle $4$: Middle-class residential with larger land tracts.   * Circle $5$: Upper-class suburban commuter zone.

• Limitation: Only accounts for distance from the CBD; considered too rigid for modern realities.

hoit Sector Model ($1939$)

• Origins: Proposed by hoit to address Burgess's shortcomings by introducing "direction" as a factor.

• Structure: Cities develop in wedge-shaped sectors along major transportation routes, specifically electric streetcars and elevated trains.

• Spatial Arrangement: Low-income housing remains near industry, while middle and upper classes extend outward along transport lines.

• Limitation: Assumes city development follows a highly predictable, geometric manner.

Multiple Nuclei Model ($1940s$)

• Origins: Developed by chony Harris and Edward Olman in response to the rise of automobiles.

• Structure: Growth occurs independently around several distinct nodes or nuclei rather than a single CBD.

• Factors for Nodes:   * Specialized activities requiring specific infrastructure.   * Economic benefits of industries clustering together.   * Displacement of residents due to negative industrial consequences (noise/pollution).

• Examples: Los Angeles, California and Houston, Texas.

Galactic City Model

• Structure: Represents a decentralized city featuring "Edge Cities" that provide services once exclusive to the CBD.

• Connectivity: All parts of the city are linked through highway belts or beltways.

• Example: Atlanta, Georgia and its Interstate $285$ Beltway.

• Limitation: Increasingly obsolete due to the internet and remote work reducing the importance of physical beltways.

Latin American Model

• Basis: Influenced by $16th$-century Spain colonial policies and specifically the structure of Mexico City.

• Components: Combines concentric and wedge zones with a central CBD and a separate Market area.

• Key Features:   * An elite "spine" of high-quality infrastructure and housing extends from the CBD.   * disamenity zones: Edge locations (barros) for the poorest residents with minimal amenities like running water.

Southeast Asian Model

• Structure: Organized around water-based trading ports established by colonial powers instead of a central CBD.

• Zoning: High-class residential areas are situated close to the port and government sectors.

• Market Gardening Zone: A unique area accommodating light agriculture.

• Example: Manila, Philippines.

Subsaharan African Model

• Structure: Features three distinct CBDs: Colonial, Traditional Marketplace, and Modernizing.

• Zoning: Neighborhoods are defined by ethnic identities and are located near mining or manufacturing zones.

• Periphery: The outermost areas consist of impoverished shanty towns and squatter settlements.

• Example: Legos, Nigeria.