sustainable communities and lifestyles the impacts of u.s. “urban sprawl” what is it? “the...

Sustainable Communities and Lifestyles

The Impacts of U.S. “Urban Sprawl”

• What is it? “The Suburbs”• When did it begin and why? • How is the environment changed?• What are the consequences of “exurban

migration”?• Why Clustered Living and Development”?

Urban Sprawl

• Expansion of metropolitan areas (suburbs).• More houses, shopping centers and highways

farther from city centers.• Lack of overall land-use planning.• Facilitates extravagant consumption of resources.

– Energy– Materials

• Loss of “green-space” and farmland• Increased pollution (smog)

Factors That Contributed To Urban Sprawl - post-WWII

City overcrowding & pollutionFarmland sale and conversionCheap accessible mortgagesEasy car ownershipPost-war savings

Highway Trust Fund (1956)

Rate of Urbanization in Texas

0102030405060708090

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1910

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% Urban% RuralTexas Pop.

Country Mouse to City Mouse

Environmental Impacts of Urban Sprawl

• Development on forests and grasslands =– Reduced water quality– Reduced air quality– Fewer renewable resources– Wildlife loss (biodiversity loss)

• Hydrologic Cycle Modification– Increased runoff, erosion, flooding– Reduced water quality and water table level

• Ecosystem simplification and destabilization

Wildlife Loss Mechanismsof Highways and Development

• Direct habitat destruction

• Habitat fragmentation– Territories too small– Migration interrupted

• Access to water prevented

• Highway fatalities (them not us)

Urban Wildlife Management Problems

• Changed societal attitudes towards animals

• Urban cougar, deer, and geese populations

Environmental Impacts of Urban Sprawl(Figure 24-6)

Indicators of Urban Blight/Decay• Economic and ethnic segregation• Eroding tax base• Loss of social services• Lowered property values• Higher property tax rates (improvements will result in more taxes)

• Deterioration of central city infrastructure• Decline in education quality• Loss of jobs and self esteem• More drug trafficking and violent crime

Consequence of Exurban Migration= Urban Blight/Decay!

What Makes Cities Livable?Why Clustered Living?

• Minimal commuting distance

• Reduced automobile traffic

• Improved access by foot or bicycle

• Improve mass transit

• Efficient central heating opportunities

• Heterogeneity of residences and businesses (cultural diversity)

• People meet people not cars

City Rehabilitation and Clustered Development

• Integrated living, working and recreational spaces (close proximity of shops, residences, services …)

• Affordable housing (smaller; town-homes)• Use alternative energy sources (e.g. solar).• Provisions for pedestrian and bicycle traffic.• Self-sufficiency in provision of food• Protection of sensitive habitats• Stable population