Watershed and Human Impact

1. What is the difference between

fresh and saltwater?

2. What are examples of surface

and groundwater?

3. What are the parts of an aquifer?
4. What are some different types
of water pollution?
5. How can water be conserved?

Essential Questions:

Water Cycle Review

●Also called the hydrologic cycle
●The journey water takes as it

circulates from the land to the air
and back again.

●Involves evaporation,

condensation, and precipitation.

●Repeats as a never-ending cycle

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Natural Resource

●Naturally occurring substances

such a mineral, forest, water, and
land that are used by humans.
Renewable Resource

●A resource that can be used

repeatedly because it is replaced
naturally (cycle).

●Water fits both these criteria.

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Watershed

●Basin-like land formation defined

by highpoints and divides that
descend into lower elevations.

●Carries water from the land

after rainfall or snow melts.

●Drains all the water into a

common outlet such as a
stream channel, a reservoir, or
bay

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Fresh Water
●Very low amounts of dissolved

salt – less than 1%

●Examples:

○Ponds and Lakes
○Streams and Rivers
○Wetlands

●Makes up 3% of Earth’s water

resources, including ice caps and
glaciers

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Salt Water

●High concentrations of salt
●3.5% of the weight of seawater

comes from dissolved salt
(salinity)

●Examples:

○Oceans
○Seas

●Makes up 97% of Earth’s water

resources

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Surface Water
●Water on the surface of the planet
●Examples:

○Ponds and Lakes
○Streams and Rivers
○Wetlands
○Oceans

●Replenished by precipitation and
groundwater

●More prone to pollution than
groundwater

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Groundwater

●Water found underground in

cracks and spaces in soil, sand,
and rock.

●Stored in and moves slowly

through aquifers

●More than 50% of the people in

the U.S. get their drinking
water from groundwater.

●Largest use is irrigating crops
●Less prone to pollution

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100x more water found in

groundwater than surface water

Groundwater Vocabulary

●Permeable – rock layers or

sediments that transmit
groundwater freely
a. Must include spaces (pores)

throughout the rock layer

b. Pores must be connected

●Impermeable – few or no

connected pore spaces, such as
clay

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Permeable

Impermeable

Groundwater Vocabulary

●Zone of Aeration – region between

the earth’s surface and the water
table

●Water Table – the upper surface of

the Zone of Saturation (can move
up or down depending on
rainfall)

●Zone of Saturation – region in the

ground in which the pore spaces
are filled with water

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Aquifers
●Found underground
●Made of gravel, sand,

sandstone, or limestone

●Water can move through these

materials because they have
large connected spaces
(pores) that make them
permeable.

●The flow of water depends on

the size of the spaces and how
well they are connected.

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Well
●An excavation or structure created

in the ground by digging, which
accesses groundwater in an
aquifer.

●The well water is drawn by a pump

that is raised mechanically or by
hand.

●How is the well depth determined?

What might make a well “go dry?”

●Replenished by precipitation

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Artesian Well
●A place in the ground where

water flows up to the surface
because of natural pressure
without being pumped.

●Water comes directly from the

aquifer or porous rock layer.

●Gravity creates the natural

pressure.

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Impermeable rock layer

Water Pollution
●Contamination of bodies of

water, often by human activity,
which affects watersheds

●Occurs when pollutants are

discharged directly or
indirectly into the water.

●Along with air pollution, water

pollution is the second biggest
environmental concern.

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Point Source Pollution
When the pollutants come from a
single location such as dumping
chemicals into a river.

Nonpoint Source Pollution
When pollutants are introduced into
the environment over a large,
widespread area such as
agricultural runoff.

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Types of Water Pollution
●Surface water
●Oil spillage
●Chemical
●Groundwater
●Thermal
●Agricultural

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Surface Water Pollution

●Hazardous substances coming into

contact with surface water

●Dissolves or mixes physically with

the water

●Examples: Humans dumping trash

into the waterways, especially
objects that are swept down storm
drains.

●Also, sewage

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Oil Pollution
●Release of liquid petroleum

hydrocarbons (oil) into the water

●Especially harmful to marine

and other wildlife

●Usually localized, but can

spread

●Examples: oil spills

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Chemical Water Pollution

●Chemicals from industries and

farmers that run off into the
waterways.

●Examples: metals and solvents

from industries

●Also, chemicals that control

weeds, insects, and pests

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Groundwater Pollution
●Pesticides and chemicals wash

deep into the ground by rain water

●Can get into the aquifers, thus

polluting the groundwater

●Anything on the surface can

eventually work its way down to
the groundwater.

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Groundwater Pollution
(continued)
●Plume – the area of groundwater

affected by the contamination

●Look at the diagram and observe

the amount of contamination in
relationship to the point pollution.

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Thermal Water Pollution

●The rise or fall in the

temperature of a natural body
of water.

●Changes the physical

properties of water, particularly
the amount of dissolved
oxygen in the water.

●Decreases fish population and

increases death to wildlife

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Agricultural Pollution
●Sediments washing off fields

are the largest source of
agricultural pollution in the
U.S.

●Sediments increase the cost of

treating drinking water and can
also clog fish gills, reducing
their resistance to disease.

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Overuse and Waste

●Irrigation uses 30% of all

freshwater in the U.S.

●Swimming pools and water

parks

●Golf courses
●Washing cars
●Watering the lawn

What other ways do you overuse

or waste water where you live?

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Estimated % of water used at home

Land Subsidence

●Withdrawing groundwater

causing the land to sink

●Causes flooding problems
●Causes a shift in the

foundations of buildings, which
can lead to their destruction

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Complete the diagrams in
your notebook by writing the
following terms in the correct
areas

Check for Understanding

Can you…

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compare fresh and salt water, including examples?

identify the differences between surface and groundwater, including
examples?

draw and label the parts of an aquifer?

recall six different types of water pollution?

generate ideas for reducing water pollution?