Land Use

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Chapter 14

• Land Use

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PUZZLE

• Four switches can be turned on or off. One is the
  light switch for the incandescent overhead light
  in the next room, which is initially off, but you
  don't know which. The other three switches do
  nothing. From the room with the switches in it,
  you can't see whether the light in the next room
  is turned on or off. You may flip the switches as
  often and as many times as you like, but once you
  enter the next room to check on the light, you
  must be able to say which switch controls the
  light without flipping the switches any further.
  (And you can't open the door without entering,
  either!) How can you determine which switch
  controls the light?

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Land Use

• Land cover is what you find on a patch of land
• Ex. forest, field of grain, parking lot

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Urban/Suburban/Rural

• Urban city, or area that contains 2,500 or more
  people
• Suburban residential area surrounding a city
• Rural area of open land that is often used for
  farming

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History

• Until about 1850, most people lived in rural
  areas.
• Many were farmers
• The Industrial Revolution changed this pattern as
  machinery made it possible for fewer people to
  operate a farm or grain mill and better
  transportation allowed manufacturers to be
  located farther from their customers.

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History

• Thousands of rural jobs were eliminated, and many
  people had to move to cities to find jobs.
• Urban areas grew rapidly during the 20th century
  and spread over more land.
• The movement of people from rural to urban areas
  happened in developed countries between 1880 and
  1950.
• It is occurring rapidly in developing countries
  now.

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Land Area

• Area of land needed to support one person depends
  on
• Climate
• Standard of living
• How efficiently resources are used

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Urbanization

• Urbanization increase in the density of people
  in urban areas rather than rural areas.
• People leave rural areas for more and better
  paying jobs in towns and cities.
• In developed countries, urbanization slowed in
  the second half of the 20th century.
• Over time, small towns have grown together and
  formed large urban areas called megalopolises.
• Ex. Washington D.C.-Baltimore

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• Urban areas that grow slowly are able to build
  roads and public transportation to meet the needs
  of citizens.
• Buildings, roads, and parking lots are mixed with
  green spaces.

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• Green spaces provide ecosystem services
• Ex. moderation of temperature
• infiltration of rainwater runoff
• aesthetic value

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Green Spaces

• Moderation of Temperatures
• Vegetation does not absorb as much heat
• Soil does not hold heat as long
• Infiltration of rainwater runoff
• Vegetation uses water for survival
• Water can be stored in the soil instead of all
  rainwater entering the sewer lines

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Green Spaces

• Because building a city means replacing
  vegetation with structures, the city loses the
  evaporative cooling advantages of vegetation.
• Vegetation plays a large part in keeping an area
  cool through a process called evaporative
  cooling.
• Evaporation is when liquid turns into gas.
• After the plant is done with water, dry air
  absorbs that water by turning it into gaseous
  water vapor.
• The air provides the heat that drives this
  process, so during the process, the air loses
  heat and becomes cooler.
• We experience the same type of thing when we
  sweat -- when air hits your sweaty skin, it
  absorbs the moisture and cools the air around
  you.

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Roof top gardens
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Infrastructure

• A rapidly growing population can overwhelm the
  infrastructure
• traffic jams, substandard housing, polluted air
  and water
• Infrastructure is the basic facilities of a
  country or region, such as roads, bridges,
  sewers, and railroads.
• Urban Crisis more people live in a city than its
  infrastructure can support.

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Urban Sprawl

• Urban sprawl rapid spread of a city into
  adjoining suburbs and rural areas.
• This growth results in the building of suburbs
• Many of these suburbs are built on land that was
  previously used for food production.
• Each year suburbs spread over another 1 million
  hectares (2.5 million acres) of land in the
  United States.

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Urban Sprawl

• Many cities were first built where there was
  little room for expansion.
• As the cities grew, suburbs were often built on
  marginal land, or land that is poorly suited for
  building.
• Ex.Los Angeles was built in a basin, and has
  expanded onto slopes that are prone to
  landslides.
• Structures built on marginal land can become
  difficult or impossible to repair and can be
  expensive to insure.

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Urban Sprawl

• Results of Urban Sprawl
• greater car dependence
• higher infrastructure costs
• loss of open space and agricultural lands
• more energy-intensive development
• urban core disinvestment
• traffic congestion

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Heat Islands

• Environmental conditions in the center of a city
  are different from those of the surrounding
  countryside
• Cities generate and trap more heat.
• Heat island area in which the air temperature is
  generally higher than the temperature of
  surrounding rural areas.
• Heat is generated by the infrastructure that
  makes a city run.
• Roads and buildings absorb and retain heat longer
  than vegetation does.

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Heat Islands

• Heat islands can affect local weather patterns.
• Hot air rises over a city, cools as it rises, and
  eventually produces rain clouds.
• Increased rainfall is a side effect of the heat
  island effect.
• Moderated by planting trees for shade and by
  installing rooftops that reflect heat.

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Puzzle

• What word is pronounced differently when the
  first letter is capitalized?
• In each of these puzzles, a proverb is written
  with exactly one letter of each word replaced
  with another. Can you figure out what the
  original proverb is?
• Beauts in oily shin beep.
• I pool ant has honey ale boon panted.

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Heat Island Effect

• Temperatures can differ between 1.8F (day) and
  22F (night) from rural to urban areas
• Heat islands can affect communities by increasing
  summertime peak energy demand, air conditioning
  costs, air pollution and greenhouse gas
  emissions, heat-related illness and mortality,
  and water quality.

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Heat Island Effect

• Objects can absorb and reflect light. The amount
  of light reflected is known as the albedo.
• The color of an object depends on what kind of
  light it reflects.
• Ex. a green object reflects green light and
  absorbs all the other visible colors of light.
  When we see a green object, we perceive it as
  green because it reflects the green wavelength of
  color back to our eyes.
• Darker colored objects are excellent absorbers of
  light. Black surfaces absorb almost all light.
  Lighter colored surfaces do not absorb much light
  at all -- they reflect almost all of it.

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• When an object absorbs light, it converts light
  energy to thermal energy (heat) and releases it.
• When we build and expand cities, we tend to erect
  buildings with dark surfaces and lay down asphalt
  pavement. The buildings and the pavement absorb a
  significant amount of light and emit it as heat,
  warming the city.

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Los Angeles Heat Island Effect
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Infiltration

• The way water moves through soil is called
  infiltration.
• Infiltration helps maintain water quality because
  many soils and plants filter out certain
  pollutants as water moves through them.
• An impervious surface is one that does not allow
  water to infiltrate to the soil layer.
• As water runs off of impervious areas, water can
  pick up potentially toxic substances (like oil or
  fertilizer) and carry these materials to the
  sources of our water.

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Puzzle

• So thing owl heard by tree.
• If as dot oven mill she far lazy sines.
• To onto otters at yon could hale teem no undo yon.

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Land Use-Planning

• Land-use planning is a set of policies related to
  potential uses of land that is put in place
  before an area is developed.
• The federal government requires developers to
  prepare detailed reports assessing the
  environmental impact of many projects, and the
  public has a right to comment on these reports.
• Developers, city governments, local businesses,
  and citizens often disagree about land-use plans.

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Land-Use Planning

• Unsustainable urban sprawl as a result of 
• zoning ordinances that isolate employment
  locations, shopping and services, and housing
  locations from each other 
• low-density growth planning aimed at creating
  automobile access to increasing expanses of
  land.