How much water is on earth, and what kind of water is it?
Activity 1
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The Uses of Water In your notebook create a list of the ways
that people use this precious water? Think hard! After you have at
least 10 ways that you use water turn to someone next to you and
share and compare your lists. Be sure to add your partners uses to
you list and vice versa.
Slide 4
The Uses of Water Did you include the following in your list:
Water for irrigation(farming). Water for manufacturing clothing.
Soft drinks contain water, as well as the process of making the
bottles they come in. In mining, water is often used to separate
the metal/minerals from the rest of the rock. This metal can be
found in the clothing you wear and the electronics that you
use.
Slide 5
Water in Irrigation How can water use for irrigation be helpful
and harmful?
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Questions to Consider 1. Which countries are most likely to
rely on irrigation to grow crops? Least likely? 2. In which
countries is agriculture probably the main source of commercial
income? 3. What types of domestic, or personal water systems are
countries like Cambodia and Gambia likely to have? (hint: Cambodia
has 6 litres of water per person per day, Gambia has 3 litres of
water per person per day, Canada has431 litres per person per
day!)
Slide 7
Cambodian boy using a local well to get water for his
family.
Slide 8
Cambodian girls gathering water at the local well.
Slide 9
Uses of water Over 1.4 billion people currently live in river
basins where the use of water exceeds minimum recharge levels,
leading to the disappearance of rivers and depletion of
groundwater.
Slide 10
Facts of Water Use The world's 6.9 billion people are
appropriating 54 percent of all the accessible freshwater contained
in rivers, lakes and underground aquifers.
Slide 11
Staggering Statistics The worlds population is growing by
roughly 80 million people each year. Changes in lifestyles and
eating habits in recent years are requiring more water consumption
per capita. The production of biofuels has also increased sharply
in recent years, with significant impact on water demand. Between
1,000 and 4,000 litres of water are needed to produce a single
litre of biofuel!
Slide 12
Staggering Statistics Energy demand is also accelerating, with
corresponding implications for water demand. Freshwater withdrawals
have tripled over the last 50 years. Almost 80% of diseases in so
called "developing" countries are associated with water, causing
some three million early deaths. For example, 5,000 children die
every day from diarrhea, or one every 17 seconds.
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Water Use By Country
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Proportion of Total Water Use by Country
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Earth
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If you were looking at the earth from the moon you would see
mostly blue, a bunch of white and to a lesser extent; greens and
brown. The majority of our planet is covered in water, unlike other
planets we have water in abundance. The water we have allowed life
to flourish and evolve over millions of years to where we are now.
We owe our existence to water.
Slide 17
Water exists naturally in all three states on the earths
surface. What are the 3 states of water? Solid Liquid Gas
Slide 18
Water in Liquid State Nearly all the water on earth is in
liquid form for the majority of the time. Ocean water is home to
many varieties of animals and plants but is too salty for many
creatures that live on land to drink. Land animals and plants rely
on lakes, rivers, streams and ground water for use.
Slide 19
Water in a Solid State Most of the fresh water on the planet
can be found frozen in glaciers, on mountains, as icebergs, and as
snow and ice. Antarctica and Greenland are two places that contain
ice up to 4.8 km. Many places around the globe ice can be found as
a solid for a portion of the year.
Slide 20
Water in a Gaseous State Only a tiny portion of water can be
found as a gas called water vapour. Often you cannot see the water
vapour but you can sometimes feel it as humidity. On hot summer
days that have high humidity you will feel damp and clammy. Clouds
form when water vapour condenses to form tiny droplets of water or
ice crystals.
Slide 21
Questions This picture was taken near St. Johns, Newfoundland
during the summer months. Where do you think the iceberg came from?
How do you think it was formed? NL Iceberg Action
Slide 22
Salt Water vs. Fresh Water Lab What did we learn about the
characteristics of salt water compared to that of fresh water?
Slide 23
Although both sea water and fresh water have levels of salt it
is clear that sea water is much more salty. The average salt
content in sea water is about 3.5%. In addition to salt, sea water
has many other substances in smaller amounts. Even gold and
silver!
Slide 24
What other substances can be found in fresh and salt water? In
parts of Ontario, water contains so much iron that it affects the
taste. Too much calcium and magnesium makes water hard so that it
is difficult to lather with soap. GNB Media Release
Slide 25
Did you know? The places where fresh water from rivers flows
into salt water oceans are called brackish water. The salt content
is lower then the ocean but higher then the river. Only certain
organisms can live in these water ways.
Slide 26
What does salt do to water? Have you noticed that the ocean
doesnt really freeze, unlike lakes and ponds that tend to freeze
more often? One reason why this happens in because salt in
water(salinity) changes its freezing point. This is why we often
put salt on the roads during winter months. High salinity of water
lowers its freezing point. This means salt water needs colder
temperatures in order to freeze.
Slide 27
Salt Water Salt is sodium chloride (NaCl) Weve talked about the
percentage of salt water vs. fresh water found on our planet.
(roughly 98% vs. 2%) We discovered that the salinity of water
affects density and buoyancy. Salinity is the saltiness of a body
of water or soil.
Slide 28
Density can be described as the crowdedness of the particles
that make up matter. In this case, water.
Slide 29
Density In scientific terms, density is the amount of substance
that occupies a particular space. When you refer to a substance as
being light or heavy, you are referring to the property of
density.
Slide 30
Density According to the particle theory, different substances
have different sized particles. The size of the particles
determines how many particles can fit into a given space. Because
of this, each substance has its own unique density based on
particle size.
Slide 31
Think about this Imagine two identical containers, one filled
with a liquid(water) and one filled with a gas (water vapour). Both
are the same substance therefore they have particles of the same
size. According to the particle theory, gas particles have more
space between them than liquid particles. It would be reasonable to
conclude that the density of water vapor is less than the density
of liquid water.
Slide 32
Waves We have discussed some ways that water can move when we
discussed the water cycle, however, water can move other ways too.
Waves, tides, and currents are powerful forces that interact with
the environment. What types of waves have you heard of?
Slide 33
Waves Microwaves, radio waves, sound waves, water waves Do
these different waves move the same way?
Slide 34
Making Waves Lab Part 1 1. Fill a deep pan with water. 2. Wait
until the surface is calm the blow across the surface to create
waves. 3. Sketch a picture of the waves youve created. 4.
Experiment with creating differences in the waves.
Slide 35
Making Waves Lab Part 2 1. Place a drop of food colouring in a
shallow pan of water. 2. Blow across the surface of the water. 3.
Observe how the waves distribute the food colouring around the
water. Are the currents you create similar to the current found in
the worlds oceans?
Slide 36
Making Waves Lab Part 3 1. Place a cork in a deep pan filled
with water. 2. Wait until the water is calm. 3. Blow on the water
but not on the cork directly. 4. Can you move the cork across the
pan with the waves youve created? Why or why not?
Slide 37
Waves Waves are patterns that move along the surface of the
waters surface. TIL The water itself doesnt move far, it just moves
up and down, but the waves can travel many kilometres across the
surface of the ocean! Skipping rope demonstration
Slide 38
Solar Powered Waves Waves, believe it or not, start from the
sun! The sun doesn't ever heat the Earth evenly. Some spots get
heated more than others. As some air gets heated, it becomes less
dense, and thus lighter, and naturally floats upward. This leaves
an open space for denser, colder air to rush in and take its place.
This air rush is the refreshing cool breeze you feel on a sunny
day.
Slide 39
Wind and Waves Wind is also responsible for our very powerful
waves. As wind rushes up along the water, the friction causes
ripples. Wind continues to push against these ripples in a snowball
effect that eventually creates a large wave. Essentially, this
action is a transfer of energy from the sun to the wind to the
waves.
Slide 40
Wave Strength A few factors determine how strong an individual
wave will be. These include: Speed of wind: The faster the wind is
traveling, the bigger a wave will be. Time of wind: The wave will
get larger the longer the length of time the wind is hitting it.
Distance of wind: The farther the wind travels against the wave
(known as fetch), the bigger it will be.
Slide 41
Wave height
Slide 42
Slide 43
Wave Parts When waves make their way across the water surface,
the wave swells larger. The top of the wave is called the crest.
The bottom of the wave is called the trough. The distance between
them is called the wave height and the space between each crest is
called the wavelength.
Slide 44
Waves and Energy When waves make their way across water, it is
the energy moving, not the water! If you were in the ocean on a day
with many waves, you wouldnt move any great distance, you would
just bob up and down in a circular motion!
Slide 45
Questions Why are rocks and stones found on beaches often
rounded and smooth? Would it take a long time or a short time for a
note in a bottle to travel to land if thrown from a ship at sea?
Explain. Why are waves a problem for people who live close to the
shoreline?