UNIT 8
EARTHS FRESH
WATER
How much water do we use?
140 billion gallons daily in
the United States alone
Expected to
grow
Water takes up 70% of our Earth!
97.2 % Salt Water
2.2 % Glaciers/Icecaps
0.6 % Surface/Underground
0.01 % Rivers/Lakes/Streams
0.0001 % Atmosphere
Red Book Pg. 361
Of the Fresh Water
76% Ice
12% Shallow Groundwater
11% Deep Groundwater
.34% Lakes and Rivers
.037% Water Vapor
Red Book Pg. 361
This leaves 15% of our fresh
water available for use.
.42% of all water
on Earth
Why don’t we run
out of water?
The Water Cycle
The
continuous
process by which water
moves throughout the
environment
The Water Cycle
From
oceans and
freshwater supplies
to the air, land and
back to the oceans
The Water Cycle
3 Steps to the Water Cycle
Evaporation
Condensation
Precipitation
The Water Cycle
Evaporation/Transpiration
When
water changes to
vapor or gas
The Water Cycle
Condensation
When
vapor turns to
liquid
The Water Cycle
Precipitation
Water returns
to the Earth
Rain,
snow, sleet or hail
How do people use water?
Agriculture
Irrigation for
farming
Industry Uses water to
produce objects
Uses (cont.)
Transportation
People and goods
Recreation Swimming,
boating, etc.
Fresh Water Usage Handout!
Water Usage Lab
Fill
out chart on back of lab sheet
List 10 other ways to conserve
water (#3)
In your lab report explain how
much water you could save and
how you are planning to do it.
Hint:
Use data from chart.
Water Cycle Quiz
Water Cycle Quiz
5&6. Describe 2 of the 4 steps in
the water cycle.
7. In your own words, describe the
water cycle.
8. Explain why there are water
shortages if the earth's total
water volume is constant.
Water Cycle Bonus
2 Types of fresh
water on the surface
Running
water
Standing water
Running Water
Surface
runoff - Water
that enters a river after a
heavy downfall
Watershed - Area where
runoff drains into the river
system
Watersheds
Standing Water
Lakes
and ponds
- depends on size
Reservoirs Artificial lake built
by damming a
stream or river
Quabbin Reservoir
Construction
1936-1946
412 billion gallons flooded
the Swift River valley
Largest man-made
reservoir in the world
Quabbin Reservoir (cont.)
Floods
left Prescott,
Enfield, and Greenwich
under water.
Blue Hills Reservoir
Constructed
in the early 1950s
Provided storage until 1981
Removed
due to water quality.
MA
Watersheds
The Water Cycle
What is Groundwater?
Water
that
remains in
the ground
Water beneath the Surface
Ground-
water
seeps
between
pores in
the soil
Permeable vs. Impermeable
Permeability
-The
ability of material to let
water pass through it
Permeable or Impermeable?
Impermeable
Permeable
Underground Zones
Zone
of saturation
Zone of aeration
Water table
Aquifer
Artesian well
Zone of Saturation
Underground
area where all
pores are
filled with
water
Zone of Aeration
(Unsaturated Zone)
Dry
region where the
pores are filled mostly
with air
Water table
Area
including the zone
of saturation and zone
of aeration soaked with
water
How do we bring groundwater to
the surface?
Wells - Drill a
hole below the
water table
and pump
water to the
surface
Aquifers
Layer
of permeable rocks
that allows the water to
flow sideways between
impermeable layers
Sandstone,
gravel, sand
Aquifers
Aquifers
Artesian well
Artesian well
Well
water
that flows on
its own
without
pumping
QUIZ
QUIZ
Ecology Book
Water as a universal solvent
•
•
•
•
•
•
Acid
Base
pH
Solute
Solvent
Polar molecule
Solute
•
The substance that dissolves
in a solution
Solvent
•
The liquid in which the solute
dissolves
Polar Molecule
•
A molecule that has
a negative charge at
one end and a
positive charge at
the other
Acid
•
Solution with more hydrogen
ions than hydroxide ions
Base
•
Solution with more hydroxide
than hydrogen ions
pH
•
Units by which acids and
bases are measured
•
pH less than 7 = Acid
pH greater than 7 = Base
•
Importance of Water
•
•
•
•
Resists changes in
temperature
Universal solvent
Polar molecule
Neutral pH
How do we make water
drinkable?
Public and private water supplies
often need treatment to improve
water quality
Measurement
of substances in
water besides molecules
Read from Red Book pg. 395-398
Water Quality
Appearance
and taste
Acidity
(pH)
Hardness
Hard
water does not mix well with
soap
Disease
Health
Standards
Water Quality
1. First Filtration - Screens
2. Coagulation - Alum added
3. Second Filtration
4. Chlorination - Cl added
5. Aeration - Releases gasses
6. Additional treatment - Fluoride
Treating Wastewater
1. Primary treatment
Water
slows down particles fall
out
2. Secondary treatment
Filtered
through gravel &
bacteria
3. Additional treatment
Chlorine
added