GEOGRAPHY 101

1
GEOGRAPHY 101

• Environ-mental
• Geography
• Day 16....

2
Housekeeping Items

• I'm still missing a few life cycle analyses. The
  ones I've read so far are quite enjoyable.
  However, it will take me a while to mark them
  all it's a busy time of year.
• Today and tomorrow, there are three sessions
  being held on getting input on the Campus Master
  Plan Tuesday - Bldg 356, Room 109 (Theatre),
  ?400 pm to 530 pm?? Wednesday - ?Bldg 356,
  Room 109, 1230 pm to 200 pm?? Wednesday, -
  Bldg 356, Room 109?, 400 pm to 530 pm. I
  encourage you to attend. There is also a URL
  where you can go for more information
  http//www.mala.ca/masterplan/index.asp.

3
Housekeeping Items

• Regarding answers to other questions, courtesy of
  Jeff, Lewis CFCs have been replaced with HFCs
  (hydrofluorocarbons).  HFCs do not cause ozone
  depletion (no chlorine) but unfortunately are
  just as powerful greenhouse gases as CFCs. 
• Research indicates that the ozone hole has
  stabilized (with high inter-annual variability)
  and should begin to recover, with full recovery
  by 2050 but...
• With global warming, the stratosphere will
  actually cool which could lead to more
  destruction of ozone.  With a colder stratosphere
  there could be more Polar Stratospheric Clouds
  where most of the ozone destruction takes place. 
  We will have to wait and see about that.

4
Water

• The Earth is 70 covered by water, water being
  the environment for the first life forms and also
  the crucial limiting factor for organisms.
• Water is unevenly located and is delivered
  irregularly. For this reason, people have tried
  to manipulate it diverting it into irrigation
  canals, dam reservoirs, storm drains, and flood
  protection structures.
• The Earth's water is held in five natural
  reservoirs oceans, glacial ice caps,
  groundwater, surface water (lakes, streams,
  wetland), and the atmosphere (see p. 250 for the
  percentages).

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Water

• The oceans contain 97 of all water on earth.
• Of the remaining 3 fresh water, three-quarters
  is locked up in ice sheets and glaciers. Another
  one-seventh is in the form of groundwater, which
  is not always easily accessed.
• Overall, a tiny percentage is available for human
  use and it is being gobbled up and contaminated
  (e.g. the draining and pollution of aquifers).
• Reliance on groundwater vs. surface water varies
  across Canada (about 30 of communities rely on
  groundwater).

6
Physical Properties of Water

• It can exist in three forms ice, liquid water,
  and water vapour (a gas). The molecular structure
  is different in each. It requires heat to melt
  ice and to evaporate liquid water. Condensation
  and freezing release heat energy. Water can also
  be directly transformed from ice to vapour
  through a process known as sublimation.
• The Earth is 71 water, and we ourselves are 70
  water. It is essential to life.

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Hydrological Cycle

• The movement of water on Earth is a closed cycle.
• The hydrological cycle is the transfer of water
  amongst the five reservoirs and is driven by heat
  energy from the sun.
• The falling of water from the atmosphere to the
  surface is known as precipitation.The passage of
  water to the atmosphere from plants is called
  transpiration, from surface water and land
  evaporation. Together, they are known as
  evapotranspiration.
• Surplus water on land that does not evaporate is
  called run-off, some of which infiltrates into
  the soil and hence into the stores of
  groundwater. In addition, water that is
  transported horizontally through the atmosphere
  is called advection.

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HYDROLOGICAL CYCLE
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Precipitation

• How Precipitation Forms
• Cloud droplets are only about 20 microns in
  diameter (.02 mm) and if they were to fall out of
  the cloud would be quickly evaporated in the
  unsaturated air below.
• A raindrop large enough to fall to Earth must
  have a volume equivalent to 1 million cloud
  droplets.

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Precipitation

• Rain drops of water with a diameter gt .5 mm that
  fall from a cloud. Raindrops are rarely greater
  than 5 mm in diameter.
• Drizzle water droplets lt .5 mm in diameter.
• Mist the smallest droplets that fall to the
  surface.
• Virga streaks of precipitation extending part
  way to the surface. Caused by the evaporation of
  precipitation in the atmosphere.
• Snow precipitation in the form of ice crystals.
• Sleet clear translucent ice particles.

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Precipitation

• Freezing rain / glaze if surface air
  temperatures are not cold enough to freeze rain,
  supercooled drops freeze on contact with surface.
•  Hail precipitation in the form of round balls
  of ice. Hail is formed by repeated vertical
  movements in cumulonimbus clouds with an
  abundance of supercooled water droplets. Hail
  often has concentric shells of different
  densities and opaqueness that result from
  vertical movements in the clouds.
•  Rime deposition of ice crystals formed by the
  freezing of supercooled droplets on objects with
  temperature below 0C. (frost is vapour to ice,
  rime is water to ice).
•  

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Four Main Mechanisms Promoting Precipitation

• Convectional (chimney effect caused by heating of
  moisture-laden air in the lower atmosphere)
• Orographic (cooling of air as a result of passing
  over mountains)
• Frontal (the result of interacting warm and cold
  air masses in midlatitude areas), and
• Convergent (warm, moist air being drawn into
  areas of low pressure, producing most of the
  precipitation in the tropics). Each has its own
  effects.

13
Streams and Rivers

• All streams and rivers derive their flow from
  groundwater and surface run-off (also from
  snow-pack or glaciers, in some cases). All
  streams and rivers comprise watersheds. Many have
  recom-mended watersheds as the ideal planning
  unit.
• Groundwater provides a relatively steady
  contribution to stream baseflow whereas stormflow
  is much more sporadic. Human presence on the
  landscape urbanization, land clearance, and
  channel alteration has increased the magnitude
  and frequency of flooding.

14
Groundwater

• Excluding glacial ice caps, groundwater is the
  largest reservoir of freshwater.
• Groundwater is stored in porous sediments and
  bedrock. Materials containing large amounts of
  water are called aquifers. Over-pumping of
  aquifers can lead to their depletion, as is
  occurring in the U.S. West.
• Where groundwater is in contact with the surface,
  one has numerous kinds of wetlands which form a
  very productive habitat for wildlife. However,
  farmers and developers have been filling in
  wetlands for centuries, often with the
  encouragement of governments.

15
Water Consumption

• Competition for freshwater will be one of main
  issues of the 21st century. (Already 1.5 billion
  lack access to clean and reliable sources of
  fresh water.)
• Agriculture is the principal consumer of water,
  but urbanization is a growing competitor
  especially in countries like China.
• In the U.S. 411 billion gallons are consumed
  daily. But Canadians consume even more per
  capita we are the largest per capita consumers
  of water in the world!

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Water Consumption

• The breakdown in the U.S. Is as follows
• 47.7 power generation
• 34.5 agriculture
• 10 municipal/ domestic
• 7.8 industrial
• Water use takes two forms consumptive (where
  water is not returned to the environment in
  liquid form) and non-consumptive (where it is, as
  with using water as an industrial coolant).

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Water Consumption

• There are many ways to reduce consumption of
  water (see p. 272). Key ones include
• not locating consumptive land uses in drylands
• recapturing and re-using water
• treating stormwater using natural methods before
  releasing it
• repairing infrastructure
• making appliances more efficient
• xeriscaping, and
• reducing wasteful irrigation practices.

18
Privatization of Water

• A key issue in developing nations is the ongoing
  privatization of water supplies (usually by large
  North American multinationals). In South Africa
  price increases of 300 have forced many people
  to use contaminated sources of drinking water,
  and cholera cases number in the 100s of 1000s.
• The World Bank says that, at any given time, half
  the world's people are suffering from a
  water-related ailment and that, every year,
  approximately 5 million people die from dirty
  water-related diarrhoea and from a shortage of
  water.

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Privatization of Water

• We need to move beyond a system that often treats
  water as a private usufruct right (based on prior
  appropriation or riparian rights) to treating it
  as a common property resource or commons that can
  be managed on an ecosystem basis.