Sustainable Cities: Urban Land Use & Management. Chapter 25. Key Concepts. Distribution of urban & rural populations. Factors determining urban development. Resource & environmental problems in urban areas. Effects of transportation systems on urban growth.
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Urban (metropolitan) area = town plus its suburbs
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
City = large number of people with a variety of professions
who depend on resources from the outside of city boundary
Urban growth: natural increase = births > deaths & immigration mostly from rural areas “pull factors” i.e. jobs, quality of live; & “push factors” i.e. poverty.
Increasing proportion of population: By 2050 about 66% of the world’s people will be living in urban areas.
Great increase in large cities: 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).
Increasing rapidly in developing counties: 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.
Urban growth slower in developed countries: 75% of the people live in cities. But by 2025 it will be 82%.
Poverty in urban areas increasing: 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
- “Children of Mexico City”
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
75% of the US population live in urban areas occupying 3% of the country’s land area
Land and Biodiversity
Increased surface water
& groundwater pollution
Increased use of surface
water & groundwater
Decreased storage of
Surface water &
Loss of cropland
Loss of forests &
Contaminated drinking water & air
Sky illumination at night
Loss of wetlands
Loss & fragmentation of
Increased wildlife roadkill
Increased soil erosion
Decline of downtown
in central city
Loss of tax base in central city
Energy, Air, and Climate
Increased energy use
Increased air pollution
Increased greenhouse gas
Enhanced global warming
(heat island effect)
Fewer than 320 people per square mile,
or 1 person per 2 acres on average
Suburban: Between 320 and 3,200 people per square mile, or up to 5 people per acre on average
3,200 people or more per square mile
10-county metropolitan area
Urban dweller occupy 4% of the earth’s land area, they consume 75% of the earth’s resources
Air & water pollution; (industrial & photochemical smog); waste management (landfills, groundwater contamination).
Reduction in vegetation, & wildlife, introduction of
exotic & feral domestic species.
Importation of food, energy, & materials, hence not a
Climate impacts: urban heat island
Higher crime rates
Impacts on surrounding rural areas
High population density promotes the spread of infectious
Late afternoon temperature (°C)
Late afternoon temperature (°F)
Vegetation “service”: absorb air pollutions, give off oxygen, cool the
air as water transpires, provide shade hence less AC required, reduce
soil erosion, muffles noise, provides wildlife habitat and gives us an
island of peace.
As cities grow & their water demand increases, expensive reservoirs & canals must be built and deeper wells drilled.
This leads to depletion of surface and ground water & water stress for wildlife, i.e. Colorado River.
Between 50 to 70% of the water is lost or wasted.
Because many cities are build in floodplain flood events are more frequent. Ground sealing asphalt & concrete enhances run offs & quick overload of canalized rivers or drains.
Most of the largest cities are in coastal areas, hence a raise
in sea level brings additional problems.
Higher air pollution in cities causes respiratory diseases,
Increased noise levels cause stress, including: high blood
pressure, ulcer, insomnia, increased aggression, hampers
concentrations & work efficiency, causes accidents,
Drive alone 80%
Public transit 5%
Car pool 11%
Transportation & land-use decisions are liked together &
determine: - where people live
- the distance to work and to go shopping
- how much land is paved over
- amount of air pollution & exposure
cars, scooter, bikes etc.
buses & trains
Land-use planning based on the philosophy that population
growth & economic development should be encouraged,
while neglecting the environment. This is directly linked
to property taxes which is used for schools, police, fire
department, water & sewer systems.
Therefore, local government will encourage economic
growth & developments.
Reelection terms lead to short term (thinking) projects
& problem solving.
Ecological land-use planning urge communities to use
comprehensive, regional ecological land-use to anticipate
a region’s present & future needs & problems.
Ecological land-use planning:
1. Make an environment & social inventory:
Geologicalfactors (soil type, water availability). Ecological factors (wildlife habitats, pollutions).
Economic factors (housing, transportation, industry).
Health & social factors (disease, crime & poverty).
2. Identify & prioritize goals:
Encourage or discourage economic development
Protect prime habitats, forest, & wetlands.
Reduce soil erosion.
3. Develop data base (individual layers) by using new mapping technology.
4. Develop & implement a master plan.
New cities and towns i.e. Gainesville, learn from
past mistakes. Cities could be more sustainable, energy
efficient & enjoyable.
Ecocity (green city) emphasis is placed onpreventing
pollution & reduce waste, public transportation, bike paths,
using energy & matter resource, efficient, recycling &
reuse, composting to help create soil, using solar & other
locally available renewable resources, encouraging
biodiversity by providing habitats such as planning native
trees, ponds in the backyard,
This city is People and Nature-oriented & Not car-oriented
Instrumental (utilitarian) value:
Something has a value because it is useful to us.
Hence, certain things are without a value
Intrinsic (inherent) value:
Something has a value because it exist, independently of their use to humans.
A human-centered environmental worldview where nature has only instrumental values
-Humans are the most important species
-There is always more
-All economic growth is good
-Human success depends on how humans manage things
No-problem school: there are no environmental or resource problems that cannot be solved by our creativity.
Free-market school: a global free-market with minimal government interference as the problem solver.
Stewardship school: we have an ethical responsibility to be caring and responsible stewards of the earth.
Humans should not cause the premature extinction of species
Actively protect species endangered by human activities
Some believe all species have a right to survive
We are part of, not apart from the community of life &
the ecological processes that sustain all life.
Emphasis on preserving functioning ecosystems
Humans are part of ecological processes
Humans are part of nature.
There is not always more, (resources limitation)
Some types of technology and economic growth are good, but discourage harmful ones.
Human success depends on learning how earth systems work and applying what we learn.
Deep ecology: recognize both the intrinsic &
instrumental values of nature.
Biosphere and ecosystem responsibilities
Where do things I consume come from?
What do I know about the place where I live?
How am I connected to the Earth and other living things?
What are my purpose and responsibility as a human being?