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Title: Urbanization%20and%20Sustainable%20Cities


1
Urbanization and Sustainable Cities
  • Chapter 24

2
Outline
  • Urbanization
  • Causes of Urban Growth
  • Push and Pull Factors
  • Current Urban Problems
  • Developing World
  • Developed World
  • Urban Sprawl
  • Open Space
  • Sustainable Development of the Third World

3
URBANIZATION
  • Vast majority of humanity has always lived in
    rural areas where natural resource-based
    occupations provided support.
  • Since beginning of Industrial Revolution cites
    have grown rapidly in size and power.
  • Urbanization - Increasing concentration of
    population in cites and transformation of land
    use and society to metropolitan patterns of
    organization.
  • Nearly half world population now lives in urban
    areas.

4
What Is A City ?
  • US Census Bureau considers any incorporated
    community a city, and any city with more than
    2,500 residents as urban.
  • In rural areas, most residents depend on natural
    resources for their livelihood.
  • In urban areas, most people are not directly
    dependent on natural resource-based occupations.

5
What Is A City ?
  • A village is a collection of rural households
    linked by culture, customs, family ties, and
    association with the land.
  • A city has a large enough resource base to allow
    residents to specialize in arts, crafts,
    services, or professions other than
    resource-based occupations.
  • A megacity is an urban area with more than 10
    million inhabitants.

6
World Urbanization
  • In 1850, only 2 of world population lived in
    cities.
  • By 2000, 47 of world population lived in urban
    areas.
  • Only Africa and South Asia remain predominantly
    rural.
  • Expected that 90 of population growth over the
    next 25 years will occur in less-developed
    countries.

7
Urban and Rural Growth
8
World Urbanization
  • Urban growth has been particularly dramatic in
    the largest cities, especially in the developing
    world.
  • A century ago, London was the only city with more
    than 5 million people.
  • Nineteen cites currently have populations larger
    than 5 million.

9
World Urbanization
  • Some futurists predict 93 cities with a
    population of at least 5 million by 2025.
  • Three-fourths in developing world.
  • In developing world megacities, as much as half
    of urban population are transient workers or
    residents of shanty towns.
  • By some estimates, Mexico City has a current
    population of 25 million, and grows by 750,000
    each year.

10
World Urbanization
11
CAUSES OF URBAN GROWTH
  • Two main avenues of urban growth
  • Natural Increase
  • Fueled by improved food supplies and medical
    care.
  • Immigration
  • Caused by push factors forcing people out of the
    country, and pull factors drawing them into
    cities.

12
Immigration Push Factors
  • Overpopulation
  • Economics
  • Politics
  • Racial or Religious Conflicts
  • Land Tenure
  • Changes in Agriculture
  • Large Monoculture Farms

13
Immigration Pull Factors
  • Excitement and Vitality
  • Jobs
  • Housing
  • Entertainment
  • Social Mobility and Power
  • Specialization of Professions

14
Government Policies
  • Government policies often favor urban over rural
    areas in push and pull factors.
  • Developing countries often spend majority of
    budgets on improving urban areas.
  • Major cities gain a monopoly on new jobs,
    education and general opportunities.

15
CURRENT URBAN PROBLEMS
  • Developing World
  • Uncontrollable Growth
  • Traffic and Congestion
  • Air Pollution
  • Sewer Systems and Water Pollution
  • Only 35 of urban residents in developing world
    have satisfactory sanitation.
  • About same percentage do not have safe drinking
    water.

16
Current World Problems
  • Housing
  • At least 1 million people live in slums of
    central cities and in shantytowns in the
    outskirts of cities.

17
Current World Problems
  • Developed World
  • Rapid growth of cities that accompanied
    industrialization has mostly slowed or reversed.
  • Many of the environmental problems have been
    reduced.
  • Many of major polluters have moved to developing
    countries.

18
Current World Problems
  • Developed World
  • Urban Sprawl
  • In most American metropolitan areas, the bulk of
    new housing is in large, tract developments that
    leapfrog beyond city edges in search of
    inexpensive land.
  • Consumes about 200,000 ha of US agricultural land
    annually.
  • Planning authority is often divided among many
    small local jurisdictions.

19
Urban Sprawl
  • Because many Americans live far from work, they
    consider a private automobile essential.
  • Average US driver spends 443 hours per year
    behind a steering wheel.
  • In some metropolitan areas, it is estimated
    one-third of all land is devoted to automobile
    infrastructure.
  • Traffic congestion costs US 78 billion annually
    in wasted fuel and time.

20
Urban Sprawl
  • With a reduced tax base and fewer civic leaders
    living or working in downtown areas, the city is
    unable to maintain its infrastructure.
  • Low density development of suburbs is racially
    and economically exclusionary because it provides
    no affordable housing and makes a viable public
    transit system impractical.

21
Smart Growth
  • Smart Growth makes efficient and effective use of
    land resources and existing infrastructure by
    encouraging in-fill development.
  • Also attempts to provide a variety of
    transportation options.
  • Goal is staged, managed growth that protects
    environmental quality and diversity.

22
Garden Cities and New Towns
  • New Towns - Numerous experiments to try and
    combine best features of rural village and modern
    city.
  • Ebenezer Howard (1898) proposed congestion of
    London could be relieved by moving whole
    neighborhoods to garden cities separated from the
    central city by a greenbelt of forest and fields.

23
New Urbanist Movement
  • Limit city size, or organize into modules of
    30,000 to 50,000 people.
  • Determine in advance where development will take
    place.
  • Turn shopping malls into city centers.
  • Locate everyday services more conveniently.
  • Increase jobs in a community by locating offices
    and commercial centers near suburbs.
  • Encourage walking and low-speed vehicles.

24
New Urbanist Movement
  • Promote diversity in housing designs.
  • Create housing superblocks.
  • Make cities more self-sustainable.
  • Incorporate rooftop gardens or vegetation.
  • Invite public participation in decision-making.

25
Designing For Open Space
  • Traditional suburban development typically
    divides land into a checkerboard layout of nearly
    identical 1-5 ha parcels with no designated open
    space.
  • Conservation Development - Preserves at least
    half of a subdivision as natural areas, farmland,
    or other forms of open space.

26
Designing For Open Space
27
SUSTAINABLE DEVELOPMENT IN THE THIRD WORLD
  • Many planners argue social justice and
    sustainable economic development are answers to
    urban problems.
  • Another important measure of progress may be
    institution of social welfare providing care to
    the sick and elderly.
  • Others argue the best hope for developing
    countries may be to delink from established
    international economic systems and develop
    self-sustainability.

28
Summary
  • Urbanization
  • Causes of Urban Growth
  • Push and Pull Factors
  • Current Urban Problems
  • Developing World
  • Developed World
  • Urban Sprawl
  • Open Space
  • Sustainable Development of the Third World

29
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