Geology of Table Rock - 7th - On-site Activities 2

Geology of Table Rock - 7th - On-site Activity/Interpreter Led

Grade Level: 7
Content Area: Science
Time to Complete: 75 minutes
Title of Lesson: Drainage Divides

South Carolina State Standards Addressed:

I.A.1.a.1.	Observe patterns of objects and events.
I.A.1.a.2.	Distinguish between qualitative and quantitative observations.
I.A.1.b.1.	Arrange data in sequential order.
I.A.1.c.1.	Select and use appropriate tools (metric ruler) and units (km) to measure to the unit required in a particular situation.
I.A.1.d.1.	Make inferences based on observations.
I.A.1.e.1.	Predict the results of actions based on patterns in data and experiences.
III.A.3.a.	Define groundwater, runoff, drainage divide and drainage basin (watershed).
III.A.3.b.	Infer what happens to water that does not soak into the ground or evaporate.
III.A.3.c.	Analyze the factors that affect runoff.
III.A.3.d.	Differentiate between drainage divides and drainage basins using maps or aerial photography and illustrate the relationships between groundwater and surface water in a watershed.

Lesson Description:

Students will perform a map-based activity outlining a drainage divide, a drainage basin (watershed), and also measure the direction of stream flow.

Focus Questions for Students:

1.	What is a drainage divide?
2.	How is a drainage divide found on a topographic map?
3.	What is a drainage basin (watershed)?
4.	How is a compass used to indicate stream direction?

Culminating Assessment:

Have students outline the Carrick Creek drainage basin on the Table Rock Topographic Map with a wipe-off pen.

Material/Equipment/Resources (Per Group):

Table Rock topographic map	wipe-off pens (3 different colors)
protractor	ruler
vocabulary

Teacher Preparation:

1.	Read background information.
2.	Be prepared to discuss concepts of drainage divides and drainage basins (watersheds).
3.	Be prepared to demonstrate the correct way to use a magnetic compass to measure stream direction. Keep in mind that most streams make many directional changes. Those in the Table Rock area tend to make a series of nearly right angle bends. However, by measuring from the point where a stream begins to where it enters a larger stream, you can determine its general compass direction.

Background Information:

Generally flowing in narrow valleys, mountain streams are usually small and rocky with clear, cold water and many rapids and waterfalls. Occasionally these streams will disappear below piles of rock debris and reappear as springs at the downslope side. The land area that drains into a particular stream is said to be part of that stream's drainage basin, or watershed. Higher elevation ridgelines called drainage divides separate each basin from other surrounding basins. Every stream, no matter how small, has its own drainage basin from which it gathers water from runoff and sediment from erosion. Several small tributary watersheds, when taken together, serve as the combined watershed area for larger streams. In general, larger streams tend to have larger total watersheds
In the Table Rock area, the boundary between North and South Carolina follows a major drainage divide. Streams on the South Carolina side generally flow southeast toward the Atlantic Ocean. Streams in North Carolina flow to the northwest until they enter larger rivers that eventually drain into the Mississippi River.
For further information, read the background information from the SC MAPS Teaching Manual, 2000 Edition, entitled Drainage Patterns and Watersheds (pages 1-4 to 1-5); Characteristic Landforms of the Blue Ridge (page 2-2), Rationale (page 2A-1) and Introduction (page 2A-2). Copies available from the Table Rock State Park upon request.

Procedures:

Part 1: Drainage Divides

1.	Arrange students in groups of three or four and distribute materials.
2.	On the Table Rock Topographic Map, locate the North Carolina-South Carolina boundary line. Use a wipe-off pen to trace this boundary on the map.
3.	Starting near the boundary, use another color wipe-off pen to trace the paths of four streams flowing in North Carolina.
4.	Number the streams 1 through 4; and use the compass to measure the general direction of stream flow for each.
5.	Record the stream flow direction information in the data table below.
6.	Now use a different pen and trace four streams that start near the boundary and flow in South Carolina.
7.	Number the streams and use the compass to measure the general direction of flow for each.
8.	Record the stream flow direction information in the data table below.
9.	Have each group write a short paragraph that summarizes the results from the stream flow direction data table.
10.	Note that in the Table Rock area the North Carolina-South Carolina boundary follows a natural feature-called a drainage divide.
11.	Students will use their map information to compose a working definition for a drainage divide.

Average Direction of Flow for Streams in North and South Carolina

Stream Direction as Measured with Magnetic Compass

Stream 1

Stream 2

Stream 3

Stream 4

General

N.Carolina

S.Carolina

Part 2: Drainage Basins (Watersheds)

1.	Locate Weaver Creek on the topographic map.
2.	Use your definition of drainage divides to trace, with a wipe-off pen, the divides that surround Weaver Creek. Be sure to include all the tributaries that flow into Weaver Creek as part of the Weaver Creek system.
3.	Note that the line just drawn defines the Weaver Creek drainage basin or watershed.
4.	Students will use their map information to compose a definition for a drainage basin.

Part 3. Enrichment (optional)

1.	Outline the Table Rock Reservoir Drainage Basin using the same procedures as in Part 2 (Weaver creek).