5.22 sg
Chapter 22: Urbanization and Sustainable Cities
Overview of Urbanization
Historically, most of humanity lived in rural areas, relying on natural resources.
The Industrial Revolution marked a significant shift towards urbanization.
Prediction: Over the next 30 years, 3 billion people will move to cities.
Emergence of vast urban agglomerations (mergers of municipalities) worldwide.
Urban Population Statistics
Table 22.1: Urban Share of Total Population (%)
1950: World: 29.4%, North America: 63.9%, Latin America: 41.4%, Africa: 14.4%, Asia: 17.5%, Europe: 51.3%, Oceania: 62.4%
2000: World: 46.7%, North America: 79.1%, Latin America: 75.5%, Africa: 35.6%, Asia: 37.4%, Europe: 70.8%, Oceania: 70.4%
Projected 2050: World: 67.2%, North America: 88.6%, Latin America: 86.6%, Africa: 57.7%, Asia: 64.4%, Europe: 82.2%, Oceania: 73.0%
Urbanization Trends
Graph illustrates urban and rural population changes from 1950 to 2030 across development levels:
Urban growth in more developed areas versus less developed.
Definition of a City
City Definition by U.S. Census Bureau:
Any incorporated community, urban if >2,500 residents.
Rural areas: residents depend on natural resources.
Urban areas: residents typically work in non-resource-based occupations.
Difference in settlements:
Village: Linked by culture, customs, family, land.
City: Supports specialization in various fields (arts, services).
World's Largest Cities
List of major cities with over 10 million population, e.g., Beijing, Tokyo, Delhi, and more.
Notable population statistics from 1984 to projected 2025.
Urbanization Statistics
In 1900, only 13 cities had populations exceeding 1 million; by 2016, there were 500.
Demographic shift: China leads with substantial urbanization impact.
Causes of Urban Growth
Two primary factors:
Natural Increase: Improved food supplies and sanitation.
Immigration: Influenced by push and pull factors.
Immigration Factors
Push Factors:
Overpopulation, economic issues, racial/religious conflict, land ownership issues, changes in agriculture (e.g., monoculture farms).
Pull Factors:
City vibrancy, job opportunities, housing, entertainment, social mobility, professional specialization.
Urban Challenges in Developing World
Uncontrollable Growth Issues:
Traffic congestion from rapid vehicle growth exceeding road construction.
Air pollution from poorly maintained vehicles and other sources.
Inadequate sanitation and water supply: only 35% have satisfactory sanitation, with one-third lacking safe drinking water.
Current World Housing Problems
Slum Population: Minimum of 1 billion live in inadequate tenements or shantytowns.
Squatter Towns: Informal settlements where people occupy land without ownership.
Homelessness: Around 100 million lack any form of housing.
Developed World Urban Issues
Industrialization-related urban growth has stabilized or reversed in many areas, with numerous environmental problems addressed.
Movement of major polluters and businesses to developing countries.
Urban Sprawl in Developed Areas
New housing developments often occur beyond city borders, impacting agricultural land and leading to longer commutes and reduced urban tax bases.
Improving Urban Liveability: Mass Transit
Case example: Curitiba, Brazil - a high-speed bus system designed for efficiency and accessibility.
Smart Growth Principles
Encourage efficient land resources and infrastructure use.
Focus on reducing wasted space, democratic planning, mixed land uses, and preserving natural spaces.
New Urbanism Concept
Aim to restore small-town qualities in larger cities through modular planning.
Focused accessibility to services and promoting diverse housing options.
Green Urbanism Initiatives
Transition from greenfield development to redeveloping existing cities with a focus on ecological sustainability.
Encourages infill, high density, and mixed-income housing, along with alternative transportation solutions.
Open Space Design Principles
Contrast traditional suburban layouts with conservation development promoting open spaces.
Importance of views of landscapes, wildlife, and community pathways.