South Carolina ETV

South Carolina ETV
1101 George Rogers Boulevard
Columbia, SC 29201-4761
Phone: 803-737-3545

The River Ran Through It (Grades 7- 8)

Master Teacher

Susan Yelton

Overview

This lesson will allow students to identify the processes that shape our rivers and form our lakes. Students will participate in hands-on and multimedia activities as they discover and apply the river-cutting processes of water. Congaree Swamp contains the only natural oxbow lakes still in existence in South Carolina. They are an excellent example of river migration. As students follow this lesson, it will shape their understanding of the natural processes that affect our river, lakes, and state.

SC Science/Math/English

Standards Met

Science AchievementStandards—Grade 7
III—Earth, Strand A. 1.a
III—Earth, Strand A. 4.b

Science Achievement Standards—Grade 8
III—Earth, Strand A. 6.h

Math Achievement Standards—Grade 7
V—Measurement, Strands B & C

English Achievement Standards—Grade 8
IV—Writing, Strand B

Learning Objectives

Students will be able to:

list the stages in the formation of an oxbow lake
analyze topographic maps and lithographs for evidence of river migration and former meanders
predict future locations of oxbow lakes based on current river flow

Materials

Per group of four students:

shaded relief map of South Carolina
topographic map of Congaree Swamp
Congaree Swamp lithograph (can be found in SC Maps portfolio or contact the SC Department of Natural Resources for information)
stream table
sand (Sculpting sand works best, but any clean sand will do.)
source of water for the stream table
metric ruler
map of Congaree Swamp trails (available from the Congaree Swamp National Monument office)

Technology Resources

computer with Internet access (for SCETV NatureScene Interactive site)
Optional:Averkey or other TV/computer hardware that allows the computer site to be shown on a television

ITV Series

NatureScene, Lesson 38, "Congaree Swamp National Monument"

Internet Interactive

SCETV NatureScene Interactive: South Carolina: Congaree Swamp location

Previewing Activity

Introduce the lesson by having each group use wipe-on/wipe-off markers to outline the five landform regions on the South Carolina shaded relief map. Ask students to discuss geological features that characterize each landform. Have them locate the Coastal Plain and describe the topography of the area based on the shaded relief map. Next, have students locate the Congaree River, tracing it as it winds through the Sandhills and Coastal Plain until it joins the Wateree River to become the Santee River.

Ask students, "What changes do you notice about the Congaree River as the terrain of the land gradually becomes flatter?" (Responses may vary, but may include observations such as "The river curves and bends." "The river meanders." "The river spreads out more.")

At this point, define the word floodplain—a flat elongated strip of land originating from the periodic flooding of the adjacent river. Flood plains are often characterized by unconsolidated sediment such as silt and clay.

Focus for Viewing 1

To give students a specific responsibility while viewing, ask them to listen carefully for the description of Congaree Swamp's extensive flooding.

Viewing Activity 1

Start the video just after Rudy Mancke looks at the American beech tree and talks about the fruit, beechnuts. (This is at the beginning of the video.) Begin playing the video when you hear: "This is a tree that is right on the edge of the Congaree Swamp National Monument. You see this is really a floodplain and when the Congaree gets up, it floods all the way over here; even the river is two or three miles from where we're standing. If the water gets up, it could come in here fairly rapidly...." Stop the video here.

1. Have students look at the map of the Congaree Swamp trails and try to find approximately where Rudy Mancke was standing when he was speaking. Next, have each group find this location on the Congaree Swamp topographic map. They should notice the distance that the river is from the site. Ask, "Why does it flood there?"

2. Group Assignment: Find the contour line for the lowest elevation of the swamp. What is the measure? Find the highest contour line. What does it measure? Note the elevation level difference. (Subtract the lowest elevation from the highest.)

3. The Congaree River floods about 10 times a year. Shade in the area between the contour lines to show the floodplain. In what direction is the bluff located? (The bluff is the high point where flooding does not occur.)

(Teacher's Note: Tectonic uplifting that occurred in eastern South Carolina to form the Cape Fear Arch has caused the land of South Carolina to tilt slightly to the southwest. This has influenced the tendency for South Carolina river floodplains to have high bluffs mostly on the southwestern side and low, flat floodplains on the northeastern sides.)

4. Have each group look at the Congaree Swamp lithograph and make a list of floodplain features they can locate on the map.

Focus for Viewing 2

To give students a responsibility while viewing, ask them to watch the video clip of the oxbow formation and write a description of the formation of the oxbow as shown in the clip.

Internet Viewing Activities

If you can show this Internet activity on the TV from the computer, it would be quite beneficial for the whole class. If you do not have the hardware for viewing this with the whole class, assign each group computer time to view the site.

Go to SCETV and click on the NatureScene location. At this location, click on the state of South Carolina on the map, then click "Congaree Swamp National Monument" site. In the index of the Congaree Swamp site, choose "Lay of the Land," and stop.

At this location, click on the "Take the Tour Site #5" video clip. Rudy Mancke gives an overview of floodplain characteristics and the formation of oxbow lakes. Stop the clip when he begins to discuss the birds living in this habitat. Next, click on the "Landforms" site. Stop at this location.

1. Have students read the description of floodplain processes, paying close attention to the river-cutting processes associated with oxbow lakes.

Further reading will allow each group to view the process of an oxbow forming and to read an abbreviated version of the science involved.

Show students the drawing of an oxbow lake (Activity Sheet 1).

2. Group Assignment: Use descriptive words to write a poem about the formation of an oxbow lake.

Example:

Lazy, meandering rivers
Weaving patterns across the Coastal Plain
Loops, curves, erosion
Sediment, point bars, deposition
Cut off—oxbow

Post-Viewing Activities

1. Ask each group to make a chart showing the "life of an oxbow lake. "Answers should include the following information:

Neck of meandering river is cut off
River flow is diverted
Abandoned loop (oxbow)
Sediment fills in depression
Swamp or marsh forms

2. Stream Table Group Activity: Meandering Stream Flow. Pass out Activity Sheet 2 and give each group a stream table with a source of water and sufficient sand to simulate water movement.

3. Notes on Oxbow Formation. Stream channels are constantly modified by the interaction with water and sediment. Old, mature rivers develop shallow sloped turns and twists called meanders. As rivers enter the flat Coastal Plain, they tend to curve, loop, wind, and form horseshoe-shaped meanders.

Water flow is fastest on the outside of a bend, where water is deeper and slowest on the inside of the bend, where water is shallow. When the meander becomes cut off due to river migration, flow rate of water, and sedimentation, an oxbow lake forms. Weston Lake was formed about 10,000 years ago from a bend in the Congaree.

4. Distribute Activity Sheet 3, "Locate Weston Lake," the topographic map, lithograph, and shaded relief map to each group. Have students proceed with the activity.

Action Plan

1. Students will go on a field study to the Congaree Swamp site, visiting Weston Lake, an oxbow. There they will use laptop computers to write an article about the uniqueness of the oxbow lake as a habitat. This "writing across the curriculum" may be displayed on a bulletin board, and the best ones may be submitted for publication in the school newsletter.

Note: After writings have been taken off display, students should include them in their portfolios.

2. Students will use the maps to predict the movement of the Congaree River and the formation of new oxbow lakes. Using the grid overlays (or the formula for area), students will figure the size of the floodplain now and the predicted size in the future. Using this information, each group will evaluate the current improvement plans for the Congaree Swamp National Monument and write a list of suggestions and/or improvements they think would be beneficial. Students should consider the plants and animals living in this swamp community, as well as human access to the Congaree Swamp National Monument. Each group will report their findings to the class, creating an overall class action plan for improving the Congaree Swamp National Monument as a recreational and scientific resource. The class can contact the education specialist at the Congaree Swamp National Monument and plan a meeting with him or her to discuss the current plans and the students' suggestions.

3. Finally, the class may volunteer to help with River Sweep Clean-up at the swamp as a community service project. (Check with the school administration for approval of this project.)

Extensions

1. Math: Analyze and interpret flood table data. (SC MAPS activity 6A-15 #7.)

Use lines of latitude and longitude and distance measures to locate champion trees in the floodplain.

2. Science: Make a topographic profile of the Congaree National Swamp Monument. (SC MAPS 6A-14 #6)

Compare and contrast the flora and fauna found in the floodplain and around the bluffs.

3. English/Writing: Write a letter in support of national parks, especially Congaree Swamp.

Bring in objects that represent wetland metaphors and share with the class. Following this activity, allow students to write poems about the importance of the swamp biome.