Sustainable Cities: Urban Land Use and Management

Chapter 26Miller 11th Edition

Definitions• Urban (metropolitan) area = town plus its

suburbs– City = large number of people with a variety of

professions who depend on resources from the outside of city boundary

• Rural area = an area with a population less than 2,500 people– Village = group of rural households liked by custom,

culture,family ties. Historical utilization of natural resources

Urbanization & Urban growth

• Degree of urbanization is percentage of population living in area of greater than 2,500 people

• Urban growth due to:– natural increase - births– immigration - poor are pulled to urban areas or are

pushed from rural areas

• Trends of urban growth:– Increase of 2% to 45% of people in urban areas since

1950– By 2050 about 66% of the world’s people will be living

in urban areas.

Urbanization & Urban growth

• The number of large cities is mushrooming– megacities and megalopolis

– Today, more than 400 cities have over 1 mil. or more people. 19 megacities with over 10 mil. People i.e.Tokyo (28 mil), Mexico City (18 mil), New York (17 mil).

• Most of growth in developing countries will be urban growth with all of its problems– 38% of the people in live in cities. But by 2025 it will

be 54%. Many of these cities are already short on water, have waste & pollution problems.

Urbanization & Urban GrowthUrbanization & Urban Growth

• Urban growth is slower in developed countries– 75% of the people live in cities. But by 2025 it will be

82%.

• Poverty is becoming increasingly urbanized– slums, squatter settlements and shantytowns– at least 1 billion people live in crowed slums of inner cities.

No access to water, sewer, electricity, education etc. 100 mil people are homeless & sleep on the streets

• Case study - Mexico City

Mexico CityMexico City

• The world’s second largest city with 18 million people or one in five Mexicans– severe air pollution (over 4 million cars) within a valley

that causes an estimated 100,000 premature deaths/year– high unemployment rate, close to 50%– high crime rate– over one-third (6 million) of its residents live in slums

(barrios) without running water, sewer (but running sewage), or electricity

– high infection rates i.e. salmonella, hepatitis

United States Urbanization• Migration to large central cities• Migration from cities to suburbs• Migration from north & east to south & west• Urban sprawl, growth of low-density development

on the edge of cities. Encouraged by:- availability of cheap land, (forests, agriculture fields etc.).- government loans guarantees for new single-family homes- government & state funding of highways- low-cost gasoline encourage car use- low interest mortgage

Major Spatial Patterns

• Concentric Circle City such as New York

• Sector City is the large urban area extending from San Frdancisco to San Jose, CA

• Multiple Nuclei City is Los Angeles

• Megalopolis is when separate cities join such as the Bowash

Concentric Circle ModelConcentric Circle Model

1. Central business district (CBD)

2. Deteriorating transition zone

3. Worker’s homes

4. Middle-class suburbs

5. Commuter's zone

Sector ModelSector Model

1. High-rent residential2. Intermediate-rent residential3. Low-rent residential4. Education and recreation5. Transportation6. Industrial7. Core (CBD)

Multiple-Nuclei ModelMultiple-Nuclei Model

1. CBD

2. Wholesale, light manufacturing

3. Low-rent residential

4. Intermediate-rent residential

5. High-rent residential

6. Heavy manufacturing

7. Outlying business district

8. Residential Suburb

9. Industrial Suburb

Major Urban Problems in U.S.

• Deteriorating services

• Aging infrastructures

• Budget crunches from lost tax revenues as businesses and affluent people leave

• Rising poverty with violence, drugs, decay

• Urban sprawl - growth of low-density development on edges of cities and towns– 9 consequences of “bad growth”

75% of the US population live in urban areas occupying 3% of the country’s land area

Urban Resources & Environmental ProblemsUrban Resources & Environmental Problems

• 45% of people living in 5% of land – cities – consume 75% of the world’s resources

• Urban areas depend upon imports• Benefits of urbanization:

– recycling more economically feasible

– decreased birth rates reduces environmental pressures

– per capita expenditures on environmental protection high in urban areas

– population concentration impacts biodiversity less

Urban Resource and Environmental Problems

• Destruction of plant life - what is $ value?• Cities produce little of own food• Urban heat island effect --> dust dome

– 5 ways to counteract this effect

• Water supply and flooding problems– 5 ways to reduce demand on reservoirs and

waste treatment systems

• High pollution exposure

•The enormous amount of heat generated creates an urban heat island

•Additional heat changes climate of surrounding area

Urban Resource & Environmental ProblemsUrban Resource & Environmental Problems

• Excessive noise exposure health effects– Hearing loss, hypertension, muscle tension,

migraines, headaches, higher cholesterol levels, gastric ulcers, irritability, insomnia, psychological disorders, aggression

Urban Resource & Environmental ProblemsUrban Resource & Environmental Problems• Beneficial effects:

– education– social services– medical care

• Harmful effects – infectious disease spread

• high density population• inadequate drinking and sewage system

– physical injuries – pollution exposure– Urban Sprawl

Impacts of Urban SprawlImpacts of Urban SprawlImpacts of Urban SprawlImpacts of Urban Sprawl

Land and Biodiversity

Loss of cropland

Loss of forests & grasslands

Loss of wetlands

Loss & fragmentation ofwildlife habitats

Increased wildlife road kill

Increased soil erosion

Human Healthand Aesthetics

Contaminated drinking water & air

Noise pollution

Sky illumination at night

Traffic congestion

Water

Increased runoff

Increased surface water & groundwater pollution

Increased use of surface water & groundwater

Decreased storage ofSurface water &

groundwater

Increased flooding

Decreased naturalSewage treatment

Impacts of Urban SprawlImpacts of Urban SprawlImpacts of Urban SprawlImpacts of Urban Sprawl

Energy, Air, and Climate

Increased energy useand waste

Increased air pollution

Increased greenhouse gas Emissions

Enhanced global warming

Warmer microclimate(heat island effect)

Economic Effects

Higher taxes

Decline of downtownbusiness districts

Increased unemploymentin central city

Loss of tax base in central city

Transportation and Urban DevelopmentTransportation and Urban Development

• Determines where people live, where they go to work and buy stuff, how much land is paved and exposure to air pollution

• Cities grow up if they can’t grow out; more prone to use mass transit

• Urban sprawl due to cheap gas and land and highways; dispersed car-centered cities use 10x more energy

Drive alone 80%

Other 4%

Public transit 5%

Car pool 11%

Motor vehicle concentration• Ground transportation: individual (cars, etc) and mass

(buses and rail)• U.S. has 35% of cars and trucks used for 98% of all

urban transportation• Motor scooters - effort to change to electric• Riding bicycles; less pollution and dangerous and more efficient than walking

– bicycles available for public use– bike and ride systems

Pros and Cons of Mass transit• 3% mass transit use in U.S. to 47% in Japan• 20% gasoline tax revenues to mass transit• Rapid rail, suburban trains and trolley - efficient

at high population density• High speed rail lines – replace planes, buses and

private cars; but require large government subsidies

• Bus systems more flexible than rail systems but efficient when full