Water Systems On Earth
Water is one of the most precious resources
on earth.
How Do We Use water?
Water Household Use In
Canada
Water Distribution
Thevast majority of water on Earth,
about 97 percent, is salt water
Only 3 percent of the planet’s
water is “fresh water,” ( does not
contain salt).
Two thirds of this water is frozen in
large masses of ice at the North and
South Poles, and glaciers in the high
mountaintops.
Wateris always on the move. It
evaporates into the air and falls
from clouds as rain or snow.
The best way to understand
Earth’s water supply is to study it
as a system — a system in which
water constantly moves around
between sea, sky, land, and life.
A hydrologist is a person who
studies the Earth’s water systems.
Oceanographer
An oceanographer is a
person who studies the
ocean, including such
aspects as:
Its geography
Physical components such
as currents and temperature
Marine life
Hydrosphere
Allof the water on Earth is called
the hydrosphere.
Atmosphere
Some of the earth’s water is in the
atmosphere – the environment surrounding
the earth.
Lithoshpere
Some soaks, seeps, and flows into
Earth’s lithosphere—the solid
rocky ground of Earth’s crust.
Each drop of rain that falls must go
somewhere. Some runs off the land
into the streams, rivers, ponds, lakes,
and then pours into the oceans.
Some soaks, seeps, and flows into
Earth’s lithosphere and some
appears to just“vanish” into Earth’s
atmosphere
Water Cycle
The movement of water is the result of two
common changes of state:
Evaporation - the change of state from a
liquid to a gas.
Condensation - the change of state from a
gas to a liquid.
Evaporation converts liquid water from Earth’s
surface into gaseous water vapour.
Gaseous water vapour remains in the
atmosphere until it cools. As it cools, water
vapour condenses to form clouds. Liquid and
solid water fall from the clouds as precipitation
—rain and snow.
These two changes of state make the water
cycle possible. A cycle is a series of events that
repeat themselves over a period of time, where
the events or steps always lead back to the
starting point.
Inthe water cycle, there is no beginning or
end. Water is just constantly changing form.
