Urban Models and Their Structure

Overview of Urban Models

• Urban models describe the internal structure of cities.
• Main models discussed: Burgess Concentric Zone Model, Hoyt Sector Model, Multiple Nuclei Model, Galactic City Model, Latin American Model, Southeast Asian Model, Sub-Saharan African Model.

Importance of Urban Models

• Provide insight into the internal structure of cities.
• Address how cities arrange different zones, such as residential, commercial, and industrial spaces.
• Key purpose: Understanding spatial arrangement and social dynamics within cities.

Central Business District (CBD)

• Every city consists of:
    - Central Business District
    - Industrial or commercial district
    - Residential zones
• Models progressively complex but focus on these fundamental structures.

Exam Preparation

• Essential to know:
    - Strengths and limitations of each urban model.
    - Impact of transportation innovations on urban development.
    - Spatial relationships and sectors in each model.
    - Application of bid rent theory, which states that:
  $\text{Land is most expensive in the CBD and decreases in cost as distance from the CBD increases.}$

Model 1: Burgess Concentric Zone Model

• Developed by: Ernest W. Burgess in the 1920s.
• Basis: Studied Chicago.
• Structure:
    - Circle 1: Central Business District (CBD) - transportation hub and major businesses, financial institutions, and political offices.
    - Circle 2: Zone of Transition - mixed land uses, industrial centers, low-cost housing; home to many urban poor.
    - Circle 3: Working-Class Residential Zone - housing for industrial workers; proximity to industrial sector and CBD.
    - Circle 4: Middle-Class Residential Zone - larger homes, cheaper land due to distance from CBD.
    - Circle 5: Upper-Class Residential Zone - suburban commuter zone with expensive housing.
• Limitations:
    - Too simplistic; lacks real-world application due to the rise of automotive transportation.

Model 2: Hoyt Sector Model

• Developed by: Homer Hoyt in 1939.
• Structure:
    - CBD at the center with wedges extending outward along transportation routes.
    - Lower-income housing located near industrial sectors, while middle and upper classes move away, locating along transportation corridors.
• Innovations: Electric streetcars and elevated trains facilitated movement and shaped urban growth.
• Limitations:
    - Predictable urban development; reality is more complex.

Model 3: Multiple Nuclei Model

• Developed by: Chauncey Harris and Edward Ullman in the 1940s.
• Structure:
    - CBD is no longer the only defining feature; growth occurs around multiple nodes or nuclei.
    - Cities consist of distinct functional regions that have developed independently.
• Key factors for node location:
    - Specialized activities and infrastructure needs.
    - Economic benefits for related business sectors.
    - Negative industry impacts prompting relocation away from the CBD.
• Limitations:
    - Borders of nuclei can blend, making identification of distinct areas difficult.

Model 4: Galactic City Model

• Response to: Urban sprawl and car-dependent commuting.
• Structure:
    - Decentralized influence of CBD; development of edge cities providing goods and services.
    - All parts of the city are interconnected via highways and beltways.
    - E.g., Atlanta, Georgia with Interstate 285.
• Employment in suburbs may equal or exceed that of the CBD.
• Limitations:
    - Model becoming less relevant with the rise of telecommuting and e-commerce.

Global Urban Models

• Previous models focused on North America. Other regions demand distinct models:

Model 5: Latin American Model

• Structure influenced by Spanish colonial legacies.
• Arrangement:
    - CBD established by colonial law; integrates both business and market areas.
    - Features a spine with high-quality transportation and adjacent upper-class housing.
    - Zones of maturity (middle class), in situ accretion (lower income transitional housing), and disamenity zones (poorest residents).

Model 6: Southeast Asian Model

• Influenced by colonial trading ports rather than a single CBD.
• Arrangement:
    - High-class housing near ports and governmental areas.
    - Suburbs intermingle with squatter areas and market gardening zones.
    - Exemplified by cities such as Manila.

Model 7: Sub-Saharan African Model

• Structure consists of three CBDs:
    - Colonial CBD
    - Traditional marketplace
    - Modernizing CBD
• Neighborhoods characterized by ethnic identities, close to industrial zones.
• Periphery consists of impoverished shantytowns and squatter settlements, as seen in cities like Lagos in Nigeria.

Summary

• Review of seven urban models associated with city structures.
• Importance of understanding each model's strengths and limitations, contextual factors influencing urban development, and implications for contemporary urban life.