Yakima WATERS Mini Lesson
Using Topographic Maps to Profile Stream Channels
Targets and Assessment
WA Science Standards Addressed:
 6-8 INQC Investigate
Lesson Parameters
Content Area: Geography, Stream Geomorphology
Overview: Students will use a topo map to graph the
longitudinal stream profile of Crystal Creek
Grade Level: 7-8
Assessments:
 Students will turn in their graphs; will be graded
on accuracy
Suggested Time: 30-45 minutes
Special Materials:
 Topo map of Cle Elum
Learning Outcomes:
Knowledge: Students will demonstrate how to read elevations on a topo map and will
apply that knowledge by illustrating a stream gradient
Skill: Students will be able to graph a longitudinal stream profile
Science Concept Background: Being able to interpret data and then display it to enable communication
between disciplines is essential to the scientific process. Understanding stream gradient is a crucial part of
understanding stream geomorphology and processes
Materials: Topo map of Cle Elum, graph paper, ruler, pencil
Procedure:
**Students should already have a basic knowledge of how to read topographic maps, but the concept of
contour lines and contour intervals may need to be explained again
1. Have students mark 5 points that intersect with contour lines along the stream
2. Each student should create an “x,y” table; with the x variable being the point number (i.e. 1, 2, 3…) and
they y variable being the elevation
3. Each student should then create a graph with “Distance (ft)” on the x-axis and “Elevation (ft)” on the
y-axis
4. Plot the x and y variables from the table in step 2, and use a smooth line to connect the dots
5. Wrap up with discussion of what was graphed, and what the shape of the graphed line means
Key questions: How does elevation affect stream gradient?
What is the best way to display this information?
Extension(s): This same graph could then be used to measure the slope of the stream; visual cues of the
slope could be used to guess where erosion is occurring or where it might occur
Teaching Tips: Make sure students understand how to determine elevation using contour intervals
before they begin this lesson
Supplements:
See attached Cle Elum map: Contour intervals of 50 ft, elevation in ft
Author: Erin Dilworth, Yakima WATERS Project, CWU, Fall 2009