TEKS 7.8C model the effects of human activity on groundwater and surface water in a watershed
Watersheds & Groundwater
Water is never really standing still, even when we see it in a lake or in
the ocean. The path that a drop of water takes once it hits the ground is
determined by what it hits (rock, asphalt or soft dirt), gravity, and the
topography of the land. The water drop is either absorbed into the ground to
become part of the groundwater, or flows downhill over the surface of the
ground as runoff until it becomes part of the surface water system. Streams
run together and form rivers, which eventually empty into lakes or oceans.
An area of land where all of the water drains to the same body of
water is called a watershed. You can visualize a watershed by cupping your
hands and imagine the cup they form is a valley. All the rain that falls in the
valley of your hands will run “downhill” to the bottom and form a pond.
All of the land within a watershed, even
great distances away from the receiving body
of water, is still connected to it by rainwater
runoff. Understanding this connection helps in
understanding one of the important problems of
nonpoint source pollution. This type of pollution
does not have one identifiable source of
pollution but occurs when rainfall or snowmelt
runoff moves over or through the ground. This
water picks up everything that has ended up in
or on the ground, such as: trash, dirt;
pathogens (disease causing bacteria and
viruses) from animal wastes and failing septic
systems; chemicals, such as gasoline, oil, and
antifreeze from vehicles; pesticides and
fertilizer from lawns and farm fields; heavy
metals and other materials from industrial
sites, and sediments from construction sites. All
these pollutants are carried to streams, rivers,
lakes, wetlands, or ocean waters where they
affect water quality and damage the ecosystem.
Another nonpoint source pollutant is acid rain. Acid rain is caused by
car and power plant emissions of sulfur and nitrogen compounds which react
with water and oxygen in the atmosphere. This forms the acid rain that is
then deposited back on Earth in precipitation. Acid rain has many ecological
effects, but none is greater than its impact on lakes, streams, wetlands, and
other aquatic environments. Acid rain makes waters acidic and causes them
to absorb aluminum that makes its waters toxic to crayfish, clams, fish, and
other aquatic animals. This eventually impacts many more organisms
throughout the food chain—including non-aquatic species such as birds.
Groundwater is the water found beneath the surface of the earth. It
may be flowing in between particles of soil or through cracks in rocks. Most
groundwater comes from precipitation that has soaked into the ground
through the surface soil. All groundwater eventually reappears as surface
water, either in the form of springs or by feeding directly into streams, lakes,
or estuaries (areas where rivers empty into the ocean).
Many regions of the country rely on groundwater wells for their water
supply. Groundwater is important because it supplies water to nearly half of
the households in our country and is the primary source of irrigation water
for agriculture in the United States. San Antonio gets its water from the
Edwards Aquifer. An aquifer is an underground layer of permeable rock,
sediment, or soil that contains water which can be extracted for use by using
wells.
Most people picture well water or spring water as
being exceptionally pure and good to drink because it has
been filtered and protected by the earth and is far from any
sources of contamination. Unfortunately, we have shown
the humans can pollute even the waters in the depths of
the earth and that groundwater is quite vulnerable to
contamination. Soil is simply not a food enough filter to
protect groundwater from some of the contaminants that
we have dumped on the ground over the years.
There are many activities that can lead to
groundwater contamination, including: industrial and
agricultural waste disposal, poorly designed landfills,
leaking underground storage tanks, failing septic systems,
improperly applied agricultural fertilizers and pesticides,
and the list goes on and on. Once these substances are
released on the ground, they move down through the soil
and into the groundwater. Once groundwater is
contaminated it takes a very long time, if it is even
possible, for it to purify itself.
The best way to ensure a constant supply of clean
groundwater is to protect the water now rather than trying
to clean it up later.
TEKS 7.8C model the effects of human activity on groundwater and surface water in a watershed
Watersheds & Groundwater
Read the article about watersheds and ground water and then answer the
following questions.
1. A watershed is _______________________________________________
___________________________________________________________
__________________________________________________________.
2. All of the land in a watershed is connected to the receiving body of water
by ________________________________________________________.
3. Three things that determine the path a drop of water takes when it hits
the ground are _______________________________________________
___________________________________________________________.
4. When a drop of water hits the ground it is either __________________
___________________________________________________________
___________________________________________________________
__________________________________________________________.
or _________________________________________________________
___________________________________________________________
__________________________________________________________.
5. Seven types of non-point source pollutants include: _______________
___________________________________________________________
___________________________________________________________
__________________________________________________________.
6. Nonpoint source pollution does not have _________________________
________________________________________________________ but
occurs when _________________________________________________
___________________________________________________________.
7. Groundwater is ___________________________________________ and
is important because __________________________________________
________________________________________________________ and
is the ______________________________________________________
___________________________________________________________.
8. San Antonio gets its water from _________________________________.
9. An aquifer is _________________________________________________
___________________________________________________________
___________________________________________________________.
10. Car and industrial emissions lead to _______________________ which
can be toxic to organisms and impact food chains.
11. Groundwater gets contaminated when ___________________________
___________________________________________________________
___________________________________________________________.
12. Activities that can contaminate groundwater include:
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________.
TEKS 7.8B analyze the effects of weathering, erosion, and deposition on the environment in ecoregions of Texas
TEKS 8.9C interpret topographic maps and satellite views to identify land and erosional features and predict how these features may be
reshaped by weathering
Eroding the Ecoregion
Use the words in the box to complete the graphic organizer. Each
word or phrase will be used only once.
A.
B.
C.
D.
E.
F.
G.
H.
1
2
3
4
5
6
deposition
erosion
High Plains
moving water
Piney Woods
Trans Pecos
weathering
wind
7
8
Fill in each square of the Frayer Model.
Describe the process of erosion.
List some examples of erosion.
erosion
How are Earth’s materials eroded?
What are the effects of erosion?
Complete the following:
Erosion + weathering = __________________and ______________
Earth’s materials.
Erosion + deposition = ________________ to Earth’s surface.
In your own words, describe the effects of erosion, weathering and
deposition on the environment.
________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________