Water Cycle
Weather Dynamics Unit
Science 10
Mrs. S. Pipke-Painchaud
http://www
.rspb.org/p
olicy/water
wetlands/
managem
ent/cycle.a
sp
http://ga.water.usgs.gov/edu/watercycle.html
The Water Cycle: http://wwwk12.atmos.washington.edu/k12/pilot/water_cycle/grabber2.html
• Quotation:
• “Water on earth is used over and over. The water cycle, the
continuous movement of water from ocean to air and land then back
to the ocean in a cyclic pattern, is a central concept in meteorology.
In the water cycle, the sun heats the Earth's surface water, causing
that surface water to evaporate (gas). This water vapor then rises
into the earth's atmosphere where it cools and condenses into liquid
droplets. These droplets combine and grow until they become too
heavy and fall to the earth as precipitation (liquid if rain, solid if
snow).
• Water is temporarily stored in lakes, glaciers, underground, or living
organisms. The water can move from these places by streams and
rivers, returns to the oceans, is used by plants or animals or is
evaporated directly back into the atmosphere.”
– Source: University of Washington – Water- A Never Ending Story
• http://wwwk12.atmos.washington.edu/k12/pilot/water_cycle/teacherpage.html
• Water vapour enters the atmosphere through
transpiration, evaporation and sublimation.
– Transpiration: the evaporation of water through the stomata in
the leaves.
– Evaporation: changing from a liquid to a vapour (gas)
– Sublimation: changing from a solid to a vapour (gas)
– Deposition: reverse sublimation vapour to solid
• In the cool upper atmosphere, the water vapour
condenses, forming clouds.
• Over time enough water collects to cause precipitation.
– Falls over ground
• Absorb into the ground (percolation), runoff into nearby lakes
streams, rivers or lakes (surface runoff).
• Some water percolates down to the bedrock where it becomes
groundwater. It may eventually run back to lakes or other bodies of
water.
– Some of the water in the soil moves up to the roots of the plants
by capillarity.
Source: Biology 20 Duotang – Water Cycle
Stomate on the underside of a leaf:
~ Mike Morgan
http://www.microscopyuk.net/mag/indexmag.html?http://www.microscopyuk.net/mag/articles/stomata.html
Condensation: change from a vapour
to a liquid
http://2xupph.org/album/03/12/condensation.php
• Plants obtain water from the soil.
• Animals obtain water from eating plants,
other animals or drinking it directly.
• When plants and animals die, their
decomposing bodies release water back
into the environment.
Source: Biology Duotang – Water Cycle
The Water Cycle
• Consult the following websites to review the
water cycle:
– United States Environmental Protection Agency (EPA)
– Water Cycle Animation
• http://www.epa.gov/globalwarming/kids/water_cycle_version2
.html
• Quiz
– http://www.epa.gov/globalwarming/kids/quiz_water_cycle.html
– BBC Educational Resources – Water Cycle Animation
• http://www.bbc.co.uk/schools/riversandcoasts/water_cycle/riv
ers/pg_02_flash.shtml
– Earth Diagrams
• http://earthguide.ucsd.edu/earthguide/diagrams/watercycle/
• Dr. Art’s Guide To Planet Earth
– Water Cycle
• Be sure to try each of the three activities (Watch
me Cycle, Reservoirs, and Residence Time)
• http://www.planetguide.net/book/chapter_2/water_
cycle.html
• UNESCO – World Day for Water
– Description of the Hydrological Cycle
• http://www.unesco.org/science/waterday2000/Cycl
e.htm
• The World’s Water – Is There Enough?
• “Global Run-off per Capita Year Average
– 1970 - 12.900 m3/person
– 1995 - 7.600 m3/person
•
Source: Assesment of Water Resources and Water Availability in the World;
State Hydrological Institute, St. Petersburg, Russia, Prof. I. A. Shiklomanov,
et al. 1996.” (World Day for Water)
Aral Sea – A Case of Overexploitation of Water Resources
•
Quoted from: - World Day for Water – The World’s Water – is there enough?”
• The problems of the Aral Sea provide a clear message
about over-use of water resources. Fed by the flows of
about 50 cubic kilometres of water a year from the rivers
Amu Dar’ya and Syr Dar’ya, it used to be the world’s
fourth largest inland body of water. Since 1960, much of
the flow of these rivers has been diverted for irrigation of
the cotton, rice and other crops. From that time the area
of the sea has shrunk by almost 50 per cent and salinity
has increased dramatically. The level has fallen by 15
metres, exposing large parts of the sea bed. The result
has been catastrophic for the people living in the Aral
Sea Basin.
• The fishing industry has been lost, and salts
blown from the former sea bed are toxic to
humans and detrimental to crops.
• Moreover, inefficient irrigation has caused
waterlogging and salinization. These and other
problems, such as water pollution from domestic
and industrial wastes, are set against the
background of an aquatic ecosystem which has
been largely destroyed.
Aral Sea Images
The Aral Sea
Homepage:
http://www.dfd.dlr.de/
app/land/aralsee/
• View the animation
and see the
decrease in water.
http://www.dfd.dlr.de/app/land/aralsee/chronology.html
The Hydrosphere
• Section 13.8 ~ Nelson Science 10 Textbook
– Include freshwater (2.5%) and saltwater (97.5%)
– Freshwater (of the 3%):
• 87.3% - glaciers & polar ice caps
• 12.3% - underground water
• 0.4% - surface and atm water
– Of the 0.4%
• 90% - lakes
• 9% - atmosphere
• 1% - rivers
– Source: Nelson Science 10 522
Canada & Freshwater
• We are very fortunate to live here.
– We have 0.5% of the world population
– We have 10% of the world’s freshwater supply!
• Did You Know?
– Pacific Ocean:
• Largest ocean – 46%
• Deepest ocean – 11 km deep in one place
– Arctic Ocean:
• Smallest Ocean – 2.6%
•
Nelson Science 10 522
Water Trivia
• USGS –
• http://ct.water.usgs.gov/EDUCATION/trivia.htm
– CSREES – Florida Water Quality Program
• http://waterquality.ifas.ufl.edu/Water%20primer/Triv
ia/Trivia.htm
– Water Trivia:
• http://www.sbvmwd.com/water%20conservation/w
atertrv.htm
Text Questions:
• Page 524 – 2,3,4,5,6,8
Resource Websites:
• The Water Cycle
• http://www.picadome.fcps.net/lab/currl/water_cycle
/default.htm
• University of Illinois
– Hydrological Cycle
• http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/
home.rxml
• UNESCO – World Day for Water
– http://www.unesco.org/science/waterday2000/
general.htm