1. Section #2: Urban Uses of Land

2. Urbanization the movement of people from rural areas to cities
main reason to move = finding more plentiful & better jobs
as urban populations have grown many small towns have grown together to form larger urban areas – think suburban sprawl – they’re called metropolitan areas

3. Growth of the Washington D.C.-Baltimore Area Over the Years

4. The Urban Crisis urban areas run into trouble when they grow
a rapid increase in population can lead to traffic jams, substandard housing, increases in air & water pollution
a city’s infrastructure – all the things that a society does for public use – cannot handle the crowds

5. Infrastructure roads railroads bridges canals water mains sewers
power/gas lines
fire & police stations
schools
libraries
hospitals

6. Urban Sprawl
rapid expansion of a city into the countryside around the city
results in the building of suburbs on land that was once used for food production
people in the suburbs often commute to work in the city – this increases pollution from car exhaust
in 2000, more Americans lived in the suburbs than in cities & rural areas combined
each year suburbs spread over 2.5 million acres of land in the U.S.

7. Substandard Living Conditions on the Outskirts of Hong Kong

8. Suburbs Taking Over the Farmland

9. Development of Marginal Lands
most cities were originally built where there is little room for expansion
as these cities grew, the suburbs were built on land that is poorly suited for building
examples include Los Angeles & Mexico City that were built in basins, the expansions have moved into the surrounding mountains where the slopes are prone to erosion & landslides
this is often true along coastlines as well

10. Marginal Land Along the California Coastline

11. Other Impacts of Urbanization
Creation of a HEAT ISLAND
cities both generate & trap more heat, causing the temperatures in & around a city to rise
this heat is produced by the infrastructure that makes a city run
roads & buildings both absorb & retain heat longer then vegetation

12. Heat Island over Atlanta, GA

13. Heat Islands
scientists are beginning to see that heat islands can affect local weather patterns
as the hot air rises over a city, it cools & condenses producing rain clouds & an increase in rainfall
this can then lead to flooding in city because there is very little area that can soak up the extra water
planting trees for shade & installing reflective rooftops can help

14. Land-Use Planning
determining in advance how land will be used is beneficial
these plans can map out
where homes, businesses, & factories will be built
which areas will be protected for recreation
best locations for shopping malls, sewers, electrical & water lines
placement of roads, highways, & mass transit

15. Urban Planning often controversial & complex
federal government requires developers to prepare detailed reports assessing the environmental impact of projects
the public then has a right to comment on these reports
developers, city governments, local businesses, & citizens often disagree, especially when environmentally sensitive areas are in question

16. Intelligent Design
the sophisticated tools of today use GIS (geographic information systems) to help with land-use planning
GIS is a computerized system for storing, manipulating, & viewing geographic data
planners can try different combinations of data, such as the location of sewer lines, road, & parks, & then overlay these maps on top of each other

17. Each image is a different GIS layer with specific info about Seattle, WA

18. Transportation
if you compare American to European cities, you’ll notice that most American cities were designed to be traveled with automobiles
most American cities were constructed after the automobile was invented & are almost impossible to travel without a vehicle
most European cities were built before cars & consist of narrow, compact roads

19. Transportation
mass transit systems were designed to get people where they needed to go by moving lots of people at one time with buses & trains
these save energy, reduce highway congestion, reduce air pollution, & limit the loss of land to the construction of roads & parking lots
if mass transit systems are not available, carpooling is another alternative

20. Mass Transit

21. Open Space
land within an urban area that is set aside for scenic & recreational enjoyment
include parks, public gardens, bicycle & hiking trails
often referred to as GREENBELTS if they are left in their natural condition
open spaces are environmentally beneficial & provide several valuable functions

22. Open Space
plants in these open spaces absorb carbon dioxide, produce oxygen, & filter out pollutants from the air & water
keep cities cooler in the summer
reduce drainage problems by absorbing more of the rainwater runoff from areas covered with buildings, asphalt, & concrete (less flooding)
provides a place of exercise & relaxation for city dwellers