Notes on Urbanization and Urban Patterns

Definition: Urbanization is the process by which the population of cities grows, characterized by two dimensions:
- An increase in the number of people living in cities
- An increase in the percentage of the population living in cities

Urban Population by 2000: 47% lived in cities (up from 30% in 1950)
MDCs: Approximately 75% of people live in urban areas
LDCs: About 40% of people live in urban areas, with Latin America as a notable exception.

Site and Situational Factors:
- Origin: Desired characteristics (water sources, flat land, resources) influenced early city locations.
- Function: Labor types available based on site characteristics.
- Growth: Climatic conditions and situational influence on important places enhance city expansion.
Agriculture, Government Policy & Economic Development:
- Enclosure Movement: Example of government policy leading to fewer farmers needed, hence urban migration.
- Economic Development: Shift from primary sector jobs (agriculture) to secondary and tertiary sectors attracts rural populations to cities.
Population Growth and Migration:
- Migration transitions indicate stages of urbanization and demographic shifts.
Transportation and Communication:
- Borchert’s Epochs (5 distinct periods): Each characterized by the impact of transportation technology on urbanization.
  - Sail-Wagon Epoch (1790-1830): Compact urban areas concentrated on coasts.
  - Iron Horse Epoch (1830-1870): Steam railroads lead to urban growth in key transport hubs.
  - Steel Rail Epoch (1870-1920): Industrial centers evolve, changing river city dynamics.
  - Auto-Air-Amenity Epoch (1920-1970): Rise of suburban living, with decline in rail travel.
  - High Technology Epoch (1970 - present): Advances in transportation shape modern urban growth.

Consumer Services: Aim to provide personal services; accounts for nearly half of US jobs.
- Subcategories: Retail/Wholesale, Education, Health, Leisure/Hospitality.
Business Services: Facilitate business operations; about 25% of jobs in the US.
- Examples: Financial services (FIRE sector), Professional services (management, technical expertise).
Public Services: Security and protection services, making up 16% of US employment.

Classification:
- Megalopolis: Large regions (e.g., Boswash).
- City: Functional urban area (100,000 - 1,000,000).
- Town: Smaller urban area (10,000 - 100,000).
- Hamlet: Minimal urban function (less than 500).
- Village: More functional than hamlet (500 - 2,500).
- Primate City: A country’s largest city, significantly larger than the second.
Rank-Size Rule: Settlement size inversely related to rank; often observed in MDCs but can be problematic in countries dominated by primate cities.

Concept: Describes the distribution of cities based on their functions and market area.
Market Area Determinants: Range (distance people travel) and threshold (minimum population to sustain service).
Assumptions include a flat market area, equal transportation, and an even population distribution.

Concentric Zone Model: Developed by E.W. Burgess; describes urban land use in concentric circles centered around a CBD.
Sector Model: Developed by Homer Hoyt; emphasizes pie-shaped sectors based on characteristics, focusing on income levels and residential patterns.
Multiple Nuclei Model: Introduced by C.D. Harris and E.L. Ullman; suggests urban areas develop multiple centers rather than radiating from a CBD.

Rapid urbanization leads to inadequate housing, creating squatter settlements or informal housing.
Gentrification occurs as middle-class individuals move into low-income neighborhoods, improving housing but displacing original residents.
Urban sustainability is hindered by suburban sprawl and environmental challenges like pollution and loss of agricultural land.