Purpose: |
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To describe and identify
the land use activities within a watershed by analyzing its water quality. |
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Background: |
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(This information
was taken in part from CLEAN WATER in YOUR WATERSHED: A Citizens Guide
to Watershed Protection by the Terrene Institute, Washington, D.C.
1993.) |
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A watershed is an area of land from which all the
water drains to the same location such as a stream, pond, lake, river,
wetland, or estuary. A watershed can be large, like the Mississippi
River drainage basin, or very small, such as the 40 acres that drain to
a farm pond. Large watersheds are often called basins and contain
many smaller watersheds.
Nonpoint source pollution has many different sources, usually
associated with rainfall and snowmelt runoff moving over and through
the ground, carrying natural and human-made pollutants into lakes, rivers,
streams, wetlands, estuaries, and underground water. Pollutants
accumulate in watersheds as a result of various practices and natural
events. These pollutants, while sometimes inevitable, drastically
alter the state of the ecosystem. If we can determine the type
of pollutant, then we can not only classify the source of the pollutant,
but take preventative measures to alleviate any further contamination.
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Materials: |
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candy (i.e., Skittles ®,M+Ms ®) |
plastic baggies (1 per student or per group of students; snack or sandwich
size) |
graph paper (1 sheet per student or per group of students) |
colored pencils (1 set per student or per group of students) |
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Procedure: |
- Divide the candy amongst the baggies. You may either have
1 baggie per student or 1 baggie per group of students. You
should have about 30 pieces of candy per baggie. Each baggie
represents a watershed.
- Use the table at the end of this section to initiate a discussion
about the pollution that can come from different land use activities.
- Have the class assign a pollutant (or group of pollutants) to each
color of candy. For example, brown=sediment, red=pesticides,
green=fertilizers or nitrogen. There is chart at end of this
section which gives an example of a color/contaminant chart.
- Distribute graph paper to each student (or group). Have the
students draw a bar graph of the pollutants in their watershed.
Label the x-axis with the names of the candy colors or pollutants
and the y-axis with numbers.
- Give each group a baggie with candy. Have the students separate
and count the number of each color and graph them on the paper.
The students can use colored pencils to draw in the bars. Have
the students try to determine what land use activities are occurring
in their watershed by the pollutant profile.
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Discussion: |
Discuss how each watershed is different and while some watersheds might
contain an abundance of one certain type of pollutant, that almost all
forms of pollutants can be found (even in small amounts). Can they
classify their watershed, i.e., agricultural, industrial, urban, forest?
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Issued in furtherance of Cooperative Extension
work, Acts of May 8 and June 30, 1914, in cooperation with the U.S.
Department of Agriculture, James A. Christenson, Director,
Cooperative Extension, College of Agriculture, The University of
Arizona. The University of Arizona
College of Agriculture is an Equal Opportunity employer, authorized
to provide research, educational information, and other services only
to individuals and institutions that function without regard to sex,
race, religion, color, national origin, age, Viet Nam Era Veteran's
status, or disability.
For problems or questions regarding this web contact Dr.
Kitt Farrell-Poe.
This
document was last modified:
31-Aug-2005
.
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Land use, their associated activities, and resulting pollutants.
>
Land Use |
Activities |
Pollution Problems |
Agriculture |
tillage, cultivation, pest control, fertilization, animal waste management |
sediment, nitrate, ammonia, phosphate, pesticides, bacteria |
Construction |
land clearing and grading |
sediment |
Forestry |
timber harvesting, road construction, fire control, weed control |
sediment, pesticides |
Wastewater Disposal |
septic systems |
bacteria, nitrate, phosphate |
Surface Mining |
dirt, gravel, mineral excavation |
sediment, heavy metals, acid drainage, nutrients |
Urban Storm Runoff |
automobile maintenance, lawn and garden care, painting |
oil, gas, antifreeze, nutrients, pesticides, paint |