bio 105 chapter 22
Post on 09-May-2015
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Half of the World’s People Live in Urban Areas (1)
• Urbanization• Creation and growth of urban and suburban areas• Percentage of people who live in such areas
• Urban growth • Rate of increase of urban populations• Immigration from rural areas• Pushed from rural areas to urban areas• Pulled to urban areas from rural areas
Half of the World’s People Live in Urban Areas (2)
• Push factors• Poverty• Lack of land to grow food• Declining labor market in agriculture• War, famine, conflicts
• Pull factors• Jobs, food, housing• Education• Health care
Half of the World’s People Live in Urban Areas (3)
• Four major trends1. Proportion of global population living in urban areas
is increasing2. Number and size of urban areas is mushrooming• Megacities, hypercities
3. Urban growth slower in developed countries4. Poverty is becoming increasingly urbanized; mostly
in less-developed countries
Urban Sprawl Gobbles Up the Countryside (1)
• Urban sprawl • Low-density development at edges of cities/towns
• Contributing factors to urban sprawl in the U.S.1.Ample land2.Low-cost gasoline; highways3.Tax laws encouraged home ownership4.State and local zoning laws5.Multiple political jurisdictions: poor urban planning
Urban Sprawl Gobbles Up the Countryside (2)
• Megalopolis• Bowash – Boston to Washington 800 mile urban area
• Caused many environmental and economic problems
Urbanization Has Advantages (1)
• Centers of:• Economic development• Innovation• Education• Technological advances• Jobs• Industry, commerce, transportation
Urbanization Has Advantages (2)
• Urban residents tend to have• Longer lives• Lower infant mortality• Better medical care• Better social services• More recycling programs
• Concentrating people in cities can help preserve biodiversity in rural areas
Urbanization Has Disadvantages (1)
• Huge ecological footprints• Lack vegetation• Water problems• Concentrate pollution and health problems• Excessive noise• Altered climate and experience light pollution
Life Is a Desperate Struggle for the Urban Poor in Less-Developed Countries
• Slums
• Squatter settlements/shantytowns
• Terrible living conditions• Lack basic water and sanitation• High levels of pollution
• What can governments do to help?
Cities Can Grow Outward or Upward
• Compact cities• Hong Kong, China• Tokyo, Japan• Mass transit
• Dispersed cities• U.S. and Canada• Car-centered cities
Motor Vehicles Have Advantages and Disadvantages (1)
• Advantages• Mobility and convenience• Jobs in • Production and repair of vehicles• Supplying fuel• Building roads
• Status symbol
Motor Vehicles Have Advantages and Disadvantages (2)
• Disadvantages• Accidents: 1.2 million per year, 15 million injured• Kill 50 million animals per year• Largest source of outdoor air pollution• Helped create urban sprawl• Traffic congestion
Reducing Automobile Use Is Not Easy, but It Can Be Done (1)
• Full-cost pricing: high gasoline taxes• Educate consumers first• Use funds for mass transit• Opposition from car owners and industry• Lack of good public transit is a problem
• Rapid mass transit• Difficult to pass in the United States• Strong public opposition• Dispersed nature of the U.S.
Reducing Automobile Use Is Not Easy, but It Can Be Done (2)
• Raise parking fees
• Tolls on roads, tunnels, and bridges into major cities
• Charge a fee to drive into a major city
• Car-sharing
Some Cities Are Promoting Alternatives to Car Ownership
• Bicycles
• Heavy-rail systems
• Light-rail systems
• Buses
• Rapid-rail system between urban areas
Conventional Land-Use Planning
• Land-use planning • Encourages future population growth• Encourages economic development • Revenues: property taxes
• 90% of local government revenue in the U.S.• Environmental and social consequences
• Zoning• Problems and potential benefits• Mixed-use zoning
Smart Growth Works (1)
• Smart growth • Reduces dependence
on cars• Controls and directs
sprawl• Cuts wasteful resource • Uses zoning laws to
channel growth
Case Study: Smart Growth in Portland, Oregon
• Since 1975• Population grew 50%• Urban area expanded 2%• Efficient light-rail and bus system• Abundant green space and parks• Clustered, mixed-use neighborhoods• Air pollution reduced 86%
• Greenest city in the United States
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 – area surrounding cities• Canadian cities: Vancouver and Toronto• Western European cities
New Urbanism Is Growing
• Conventional housing development
• Cluster development
• New urbanism, old villageism• Walkability• Mixed-use and diversity• Quality urban design• Environmental sustainability• Smart transportation
Case Study: New Urban Village of Vauban
• Suburb of Freiburg, Germany
• Car use heavily discouraged with high parking fees = $40,000 for a parking space
• All homes within walking distance of• Trains and other public transit• Stores, banks, restaurants, schools
• Much use of renewable energy
The Ecocity Concept: Cities for People Not Cars
• Ecocities or green cities• Build and redesign for people• Use renewable energy resources • Recycle and purify water• Use energy and matter resources efficiently• Prevent pollution and reduce waste• Recycle, reuse and compost municipal waste• Protect and support biodiversity• Urban gardens; farmers markets• Zoning and other tools for sustainability
Science Focus: Urban Indoor Farming
• Rooftop greenhouses• Sun Works: designs energy-efficient greenhouses
• Hydroponic gardens
• Skyscraper farms
• Ecological advantages and disadvantages
Case Study: A Living Building
• Living Building• Designed to fit in with local climate, vegetation, other
characteristics• Energy met solely by renewable resources• Capture, treat, reuse all water• Highly energy efficient• Esthetically pleasing
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