©The Raptor Center
Students will:
Students will:
"The care of rivers is not a question of rivers, but of the human heart." Tanaka Shozo
Ospreys live near water, both large and small bodies, most of their lives. Rivers are a part of this "osprey landscape," just as much as lakes and ponds. Rivers need not be as large as the mighty Mississippi; they can also be small country streams, even creeks. What is important for the osprey is clear shallow water with a food source, fish.
A healthy, natural river, stream, or creek is a wonderful asset to any community. The water in such a river, stream, or creek comes from precipitation or springs. Flowing overland and sometimes underground, our creeks, streams and rivers make their way to one of three watersheds found in Minnesota; Hudson Bay, the St. Lawrence Seaway, or the mighty Mississippi, the largest watershed in Minnesota and the United States. The Giants Range, a 400- foot eroded granite highland feature, running east-west for 50 miles in the northern part of the state, causes Minnesota's waters to divide three ways. This rare three-way continental divide is located just north of the town of Hibbing. The variety of streams in this state is almost infinite, due to the fact that Minnesota is a transition between the western prairie and eastern woodlands, from northern coniferous forests to the corn belt, and encompasses three continental divides.
Water naturally carries many substances including oxygen, carbon dioxide, nitrates, phosphates, calcium compounds, and sediments. The amount of each substance in a healthy river, stream or creek depends on a number of factors. Geology, topography, water velocity, water temperature, climate, and vegetation of the surrounding area are just a few of the factors which play a role in river, stream, or creek composition.
There is no easy answer for a definition of a river, creek, or even a stream! What about a brook? It seems straight forward that a river is larger than a creek, but when does one become the other? A brook is the smallest, a creek is perhaps a little larger, and a river largest---all of which are streams. According to Thomas E. Waters' book The Streams and Rivers of Minnesota, the word "creek" is only used in America and Australia. However, in Europe, the word "creek" means a small estuary or inlet on the seacoast!
Streams are a part of a larger picture, the watershed. This lesson plan will explore the physical characteristics of streams and the concept of watersheds. The water quality lesson plans (numbers 9, 10, 11) can be adapted for use as streamside studies as well as pond and lake studies; therefore water quality exercises will not be included here in this lesson plan.
Activity1. A Stream and Its Watershed.
Locate a stream in your area which you can study and visit. It would be ideal if this stream had ospreys as a community member. Show the class the topographic map of the stream. Topographic maps can be obtained at your area soil and water district office or some sporting goods stores. It is easiest to break the class into work groups and provide a map for each group to reference as you speak. Locate the stream and point out landmarks along the stream which may be familiar.
A topographic map indicates both man-made features, as well as natural features, in an area called a quadrangle. Man-made features are marked by specific symbols. One feature which is indicated on a topographic map that is not on any other type of map is the physical characteristics of the terrain. These characteristics include the elevation, as well as mountains, valleys, plains, streams, and rivers.
Elevation is usually in measured in feet and is recorded as the number of feet above sea level. Contour lines are the way topographic maps indicate elevation. These contour lines connect all points on the map of the same elevation. The contour interval is the vertical difference in feet between each contour line. Every fourth or fifth contour line is marked with a numerical value, which indicates the distance above sea level.
All bodies of water on a topographic map are indicated in blue. A contour line bends upstream when crossing a valley. Quite often the valley will have a stream at the bottom. The ground must rise away from the stream's course.
"Watershed" is the term used to describe all the land area that drains into a specific stream, river, or lake. The water may move on the soil as run-off or in the soil as groundwater. The size of a watershed may be a few hundred square yards or several hundred square miles.
2. School Watershed
Locate the topographic map for your location. What is the watershed for your school? (You may need many maps to identify your watershed.) List the names of the streams, lakes, and ponds in your watershed. Identify sources of water pollution in your watershed. How can a topographic map help predict water quality? (The topographic map may help identify the way water flows in a given area, and therefore help identify the sources of pollution.)
3. Stream Awareness
Have students describe their thoughts, feelings, and attitudes about a stream in a descriptive paragraph and charcoal or pencil drawing.
The sounds of nature can be experienced by the class as they sit next to a stream and concentrate on the various sounds around them. Students can express their reflections through many artistic expressions.
4. The Physical Stream
Break the class into small work groups. Assign each work group a section of stream to be studied. Have each group draw a map of the stream 50 meters upstream and downstream from the point of entry. Indicate the major features of the stream such as pools, riffles, large rocks, and feeder streams. Have the students include the major features of the bank--roads, rocks, trails, trees, logs. Have them use a symbol for the other teams on the stream and where they are working.
Each team should also measure: surface temperature at one-meter intervals across stream, stream temperature near the bottom in the middle of the stream and along the bank at the bottom, and record air temperature near each edge of the stream.
Have the students calculate the stream flow for their study section. Have the students measure and mark off a 100-foot distance along a straight section of their study area. If you can not find a straight 100-foot section, use 25 or 50-foot sections. Throw a cork into the water above the upstream marker of the measured section. Record the number of seconds it takes the cork to travel between the 100-foot markers. Divide the 100-foot distance by the total seconds it took the object to float between the markers.
100 ft distance v total seconds to float 100 ft. = number of feet the stick floated per second
Find the average width of the section of the stream. Measure the width of the stream at three places within the 100-foot section. Divide the total by three to get an average width of the stream section.
First measurement _____ft.Second measurement _____ft.Third measurement _____ft.Total _____ft. v 3 = ________ft. (avg. width)Find the average depth of your section of the stream. Measure the depth of the stream in at least three different spots across the stream in a straight line. Divide the total by three to get the average depth of the stream section.
First measurement _____ft.Second measurement _____ft.Third measurement _____ft.Total _____ft. v 3 = ________ft. (avg.depth)Find the number of cubic feet of water per second. Multiply the average width, average depth, and number of feet the object floated per second.
Average width in ft. X Average depth in ft. X Number of feet per second = cubic feet of water flowing per second
Have each work group present a profile report to the other work groups on the "character" of their section of the stream. You may provide cameras to students to take pictures of their section. These photos could be used in the presentations. Profile reports should include the pictures and the descriptive paragraph done in Activity #1. For the final report, each work group should create a portfolio about their section of stream complete with topographically mapped area, descriptive paragraph, pictures and physical features, along with temperatures of air and water, stream flow measurements, and a detailed description of the stream section which was studied.
DiscussionAfter the students have learned more about their section of stream, ask them to think of streams they have seen on vacation. Are they different than the streams near home? How? Ask the students what they can do to help protect water quality in their watershed. Do they think their streams in the school watershed is clean?
Extensions1. Get information about local, state, and national laws protecting water quality in the United States. Write a brief history of the U.S. Clean Water Act.
2. Waterways have many aspects of human history attached to them. Write a short skit describing the history of a local waterway.
3. Write a letter to a local politician about how important it is to you to have clean water in your area.
Book ResourcesThe Streams and Rivers of Minnesota. Thomas E. Waters, University of Minnesota Press, 1977, ISBN 0816608210.
Listening to Nature. Joseph Cornell, Dawn Publications, 1987, ISBN 0916124355.
Glossary of Stream Habitat Terms. William T. Helm, editor, 1985, American Fisheries Society, Western Division.
Other ResourcesProject Wild/Project Wild Aquatic, Jan Welsh, Coordinator, Minnesota Department of Natural Resources, Division of Fish and Wildlife, Box 7, DNR Building, 500 Lafayette Rd., St. Paul, MN 55155, 612-297-2423
Additional Links To More River Information