22.1 What Are the Major Population Trends in Urban Areas?
Half of the World’s People Live in Urban Areas
Urbanization: The creation and growth of urban and suburban areas. it is measured as the percentage of the people in a country or in the world living in such areas
Urban growth
Natural increase, in immigration from rural areas
Pushed from rural areas to urban areas
Pulled to urban areas from rural areas
Four Major Trends
The proportion of the global population living in urban areas is increasing
The number and size of the urban regions are mushrooming
Megacities
Hypercitices
Urban growth is slower in developed countries
Poverty is becoming increasingly urbanized; most developing countries
Urbanization in the United States
Four phases between 1800 and 2008
Migration from rural areas to large central cities
Migration from large major cities to suburbs and smaller cities
Migration from North and East to South and West
Migration from cities and suburbs to developed rural areas
Environmental problems decreasing
Older cities
Deteriorating services
Aging infrastructures
Urban Sprawl Gobbles Up the Countryside
Urban Sprawl: The growth of low-density development on the edges of cities and towns
Is eliminating surrounding agricultural and wildlands
The far-flung hodgepodge of buildings loosely connected only by highways
Contributing factors to urban sprawl in the U.S.
Ample land
Federal government loans
Low-cost gasoline; highways
Tax laws encouraged home ownership
State and local zoning laws
Multiple political jurisdictions: poor urban planning
Megalopolis: chain of roughly adjacent metropolitan areas; very large cities
Bowash
Urban Sprawl
Land and Biodiversity
Loss of cropland
Loss of forests and grasslands
Loss of wetlands
Loss and fragmentation of wildlife habitats
Water
Increased use of surface water and groundwater
Increased runoff and flooding
Increased surface water and groundwater pollution
Decreased natural sewage treatment
Energy, Air, and Climate
Increased energy use and waste
Increased air pollution
Increased greenhouse gas emissions
Enhanced global warming
Economic Effects
The decline of downtown Loss of forests and business districts
Increased unemployment in the central city
Loss of tax base in the central city
22.2 What Are the Major Urban Resource and Environmental Problems?
Urbanization Has Advantages
Centers of…
Economic development
Innovation
Education
Technological advances
Jobs
Urban residents tend to live longer and have a lower infant mortality rate- better access to medical care, family planning, and social services
Environmental advantages: recycling is more feasible, reduces stress on wildlife, and saves energy when relying on mass transit
Urbanization Has Disadvantages
Huge ecological footprints: consume most of Earth’s resources and produces most of the carbon dioxide emissions, high resource input of food, water, and materials resulting in high waste output
Lack of vegetation: vegetation is destroyed to make way for roads, buildings, and housing therefore cities do not benefit from the natural absorption of air pollution, oxygen output, and shade
Water problems: water demands increase, deeper well drilling, flooding due to a lot of impermeable surfaces, and destroyed wetlands
Concentrate pollution and health problems: pollution levels are higher because pollution is produced in a smaller area and cannot be dispersed and diluted
Excessive noise: urban dwellers are subject to noise pollution- any unwanted or harmful sound that interferes with hearing, causes stress, etc
Different climates experience light pollution: cities are generally warmer, rainier, and cloudier; the enormous amount of heat is generated by factories, lights, air conditioners, etc.
Life Is a Desperate Struggle for the Urban Poor in Developing Countries
Slums: areas dominated by tenements and rooming houses where several people may live in a single room
Shantytowns: shacks are built on the outskirts of town Squatter
Settlements: people take unoccupied land without permission for survival
Terrible living conditions
22.3 How Does Transportation Affect Urban Environmental Impacts?
Cities Can Grow Outward or Upward
Compact Cities: high density like Hong Kong, Tokyo where people get around by foot, bike, or mass transit, many high-rise apartment buildings
Dispersed Cities: the city is more spread own because of plentiful land, cheap gasoline, and a network of highway systems
Car-Centered Cities: ample land is available for outward expansion resulting in urban sprawl, and passenger vehicles are the main mode of transportation
Motor Vehicles
Advantages
Mobility
Convenient
Economic gain for car industries
Helps create urban sprawl
Disadvantages
Many deaths from crashes
Increased greenhouse gases
Increased photochemical smog
Congestion
Reducing Automobile Use Is Not Easy, but It Can Be Done
Full-cost pricing: high gasoline taxes
Difficult to pass in the United States
Strong public opposition
Mass transit is not an option in most cities
Dispersed nature of the U.S.
Raise parking fees
Tolls on roads, tunnels, and bridges into major cities
Car-sharing
Charge a fee to drive into a major city
It is working in some cities
22.4 How Important Is Urban Land Use Planning?
Conventional Land-Use Planning
Land-use planning: To determine the best present and future use of land
Encourages future population growth
Economic development
Revenues: property taxes
Environmental and social consequences
Zoning
parcels of land are designated for specific uses
Mixed-use zoning
SmartGrowth: a way to encourage more environmentally sustainable development; encourages clustered, mixed-use neighborhoods
Reduces dependence on cars
Controls and directs sprawl
Cuts wasteful resource
Smart Growth Tools
Limits and Regulations
Limit building permits
Urban growth boundaries
Greenbelts around cities
Public review of new development
Zoning
Encourage mixed use of housing and small businesses
Concentrate development along mass transportation routes
Promote high-density cluster housing developments
Planning
Ecological land-use planning
Environmental impact analysis
Integrated regional planning
State and national planning
Protection
Preserve existing open space
Buy a new open space
Buy development rights that prohibit certain types of development on land parcels
Taxes
Tax land, not buildings
Taxes Tax land on the value of actual use (such as forest and agriculture) instead of on the highest value as developed land
Tax Breaks
For owners agreeing not to allow certain types of development (conservation easements)
For cleaning up and developing Planning abandoned urban sites (brownfields)
Revitalization and New Growth
Revitalize existing towns and cities
Build well-planned new towns and villages within cities
Preserving and Using Open Space
Urban growth boundary
U.S. states: Washington, Oregon, and Tennessee
Municipal parks
U.S. cities: New York City and San Francisco
Greenbelts
Canadian cities: Vancouver and Toronto
Western European cities
22.5 How Can Cities Become More Sustainable and Livable?
New Urbanism is Growing
Conventional housing development
Cluster development: High-density housing units are concentrated on one portion of a parcel and the rest of the land is used for commonly shared open space (live, work, play communities)
New urbanism, old villageism
Walkability: most stores and recreational activities located within 10 minute's walk of homes and apartments
Mixed Use and Diversity: provides a mix of pedestrian-friendly shops, offices, and homes to encourage people of all ages and races to move in
Quality Urban Design: emphasizes beauty, aesthetics, and architect
Environmental Sustainability: based on development and minimal env impact
Smart Transportation: well-designed train and bus systems connecting neighborhoods, towns, and cities