1. Land Use

2. Land Use 29% of the earth is land 29% forests and woodlands
27% range and pastures
11% cropland
33% tundra, marsh, desert, urban areas, bare rock, ice or snow

3. Forest Use
More than ½ converted to cropland, pasture, settlements, and wasteland
Ecological roles?
Used for:
~25% of world’s forests are actively managed for wood production.
Ecological roles? Regulating climate, controlling water runoff, providing food and shelter for wildlife, and purifying air.
Used for: Fuel, construction materials, paper products

4. Forest Management Harvesting methods Selective cutting
Seed tree cutting
Strip cutting
Clear cutting

5. Urbanization & Urban growth
Urban area-contains more than 1000 people per square mile
Urban growth due to:
natural increase - births
immigration
Trends of urban growth:
~75% of people in developed countries live in urban areas
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.
- poor are pulled to urban areas or are pushed from rural areas

6. 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 (35.7 mil), Mexico City (18 mil), New York (19 mil).

7. Urbanization & Urban Growth
Developing countries-most will be urban growth
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

8. Mexico City
Tied for 2nd largest city with 19 million people (1 in 5 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 1/3 (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

9. Urban Resources & Environmental Problems
50% of people living in 5% of land – cities – consume 75% of the world’s resources
Urban areas depend upon imports

10. Urban Resource and Environmental Problems
Destruction of plant life - what is $ value?
Cities produce little of own food
Urban heat island effect --> dust dome
Water supply and flooding problems
High pollution exposure

12. Urban 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

13. Benefits of urbanization
recycling more economically feasible
decreased birth rates reduces environmental pressures
population concentration impacts biodiversity less

14. 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.
Main causes:
Automobiles and highway construction
Living costs
Urban blight (positive feedback)
Government policies
Highway Trust Fund
Living costs cheaper
Urban blight: cities forced to reduce services, raise tax rates, or both; crime rates increase; infrastructure deteriorates
Government policies: funded by federal gasoline tax, pays for construction and maintenance of roads and highways

15. Impacts of Urban Sprawl
Fig. 25-8
p. 666

16. Impacts of Urban Sprawl

17. Motor vehicle concentration
Ground transportation: individual (cars, etc) and mass (buses and rail)
Drive alone 80%
Other 4%
Public transit 5%
Car pool 11%

18. Pros and Cons of Mass transit
3% mass transit use in U.S. to 47% in Japan
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

19. Alternatives to Urban Land Use?
Smart Growth-efficient use of land resources and existing urban infrastructure
Using zoning laws to prevent sprawl, direct growth in certain areas
Mixed land uses
Create a range of housing opportunities and choices
Create walkable neighborhoods
Encourage community and stakeholder collaboration in development decisions
Take advantage of compact building design
Foster distinctive, attractive communities with a strong sense of place
Preserve open space, farmland, natural beauty, and critical environmental areas
Provide a variety of transportation choices
Strengthen and direct development toward existing communities
Make development decisions predictable, fair, cost effective (no cookie cutters)