Key terms revision

1. Urban Environments
key terms revision

2. Table of Contents
∗ urbanization
∗ centripetal vs. centrifugal
movements
∗ rural-urban migration
∗ gentrification
∗ re-urbanization/urban
renewal
∗ suburbanization
∗ urban sprawl
Urban Environments
Key Terms List
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∗ global mega-city
∗ urban land use/location theory
∗ CBD
∗ inner city
∗ brownfield sites
∗ greenfield sites
∗ urban stress
∗ urban microclimate

3. Table of Contents
∗ The proportion of the world’s population who live in rural
areas has been decreasing as compared to the proportion
of the world’s population who live in urban areas.
∗ The process by which this proportion continues to rise and
more and more people move to cities is called urbanization.
∗ Natural increase (more births than deaths) also contributes to
urbanization as more babies are born in cities and rural to urban
migration continues.
Urbanization

4. Table of Contents
∗ Push and pull factors
∗ Droughts, natural hazards and desertification and high
birthrates have all led to increasing the push factors which
cause people to move to urban areas
∗ Access to jobs and steady food and water supply lead to pull
factors which draw people into urban environments.
∗ As demand for land in inner cities goes up, prices also goes
up which pushes some people out and causes
suburbanization.
Centripetal and centrifugal movements
/ rural – urban migration

5. Table of Contents
∗ When higher classes want to move from suburban areas
to urban areas, parts of a city can be gentrified. This is
the process whereby increasing rents do to increasing
demand prices some people out of the area and nicer
shops, restaurants and services move in to make the area
nicer. When this happens, crime rates tend to fall,
physical disorder decreases and new constructions often
follows.
Gentrification/re-urbanization
urban renewal

6. Table of Contents
∗ As rents in the centre of a city increases, commuters seeking to have
small plots of land, gardens/backyards move to the rural-urban fringe.
Often this includes other towns and villages that were once separate
from the urban area. Eventually they become part of the urban area
as most of the people work in the city rather than the suburban area
(village/town) they live in.
∗ As cities develop ring roads and access routs from the far reaches of
the suburbs, it become easier to commute and if the economy of the
city can support it, urban sprawl can grow and grow.
Suburbanization/urban sprawl

7. Table of Contents
∗ Megacities are defined as urban areas of 10 million people or
more.
∗ It tends to include the greater metropolitan area of a city,
which includes the suburban towns and even other cities…
∗ For instance, Jersey City and Newark are separate cities
from New York City but could be (but may not be)
considered part of the greater New York Metropolitan
area, which is a megacity of approximately 22 million
people.
∗ Many of the world’s megacities are growing rapidly in Asia
Megacity

8. Table of Contents
∗ The sector models of Burgess and Hoyt represent aspects of
location theory.
∗ There may also be multiple nuclei in a city if there is one
commercial centre and a different cultural or historic centre.
∗ In the location theory, which has evolved over time, the value
of land is predicted based on distance from the city centre,
industrial areas, transportation routs, prevailing winds and the
relief of the land.
Urban Land Use / Location Theory

9. Table of Contents
∗ The CBD is the commercial and business centre/heart of a city.
∗ Building are usually built higher in the CBD than other districts due to high
cost of land.
∗ Due to higher volume of footfall, CBD buildings often have shops on the
first floor, often high visibility boutique shops.
∗ Office buildings for Banks, insurance firms and the like are likely to want
CBD addresses.
∗ Low profit margin businesses like grocery stores may be located
underground or be small with excellent space efficiency. Department
stores make have multiple floors.
∗ It is often the historic and tourist centre as well, but doesn’t have to be
under the theory of multiple nuclei.
Central Business District

10. Table of Contents
∗ This is a term used to describe a specific area of the
Burgess model of urban land use. It refers to an area of
generally low-income housing, perhaps even public
housing projects that were designed for workers of the
factory district on the outskirts of the CBD.
∗ In a Hoyt sector model, it would be the residential area
closest to the industrial area and would again be low-
income housing.
Inner City

11. Table of Contents
∗ Brownfield Sites: Building on a site which was previously
industrial
∗ This is common in cities which are post-industrial, especially
in MEDCs where land towards the city centre is highly
valued but, perhaps, expensive to clean up to prepare for
new construction. Brownfield sites are a possible solution
to land shortages in cities which have high demand for land
and can help gentrify an area.
Brownfield Sites

12. Table of Contents
∗ Greenfield Sites: Building on a site which was not
previously build on, perhaps a forest, agricultural or
grassland area.
∗ Greenfield sites are cheaper to build on in the short term
because there is no industrial waste to clean up.
∗ Building on greenfield sites may decrease land value in the
surrounding land which would no longer be near a
greenfield site.
Greenfield Sites

13. Table of Contents
∗ The environmental quality and health issues that affect LEDCs, but it also
speaks about how social factors affect the well being of citizens.
∗ Air pollution: Increases in industry and car ownership account for the high
levels of carbon dioxide into the air, reducing air quality.
∗ Water pollution: The increased surface run-off due to the flat surfaces and
lack of soil in cities, as well as the creation of sewage systems take toxic
chemicals directly to the river.
∗ Social Stress: Individuals in cities are exposed to many different factors such
as crime, traffic congestion, housing shortages and ethnical divisions. These
factors affect the well being and performance of individuals in society.
Urban Stress

14. Table of Contents
∗ A microclimate is any area that has a different climate than the
surrounding area.
∗ Usually it is due to a geographical feature or relief. Bodies of water, valleys
and mountains may all experience microclimates.
∗ An urban microclimate is one who’s temperature and possibly rainfall are
different specifically because it is an urban area which a lower albedo.
∗ This typically causes higher temperatures, especially at night when the suns
energy is radiated back into the air.
∗ The effects of urban microclimates can be reduced by increasing green space
and tree cover as well as simple things like painting rooftops white or using
materials that reflect rather than absorb radiation.
Urban Microclimate
(urban heat island effect)