Water: Middle School
Exercise IV. Map Interpretation of Streams in the Landscape
What are all these lines anyway?
- Contour line:
- A line on a map that connects points on the land's surface that have the same elevation. If you were to walk along a contour line, you would not go uphill or downhill at all.
- A line that runs perpendicular to a contour line. If you were to walk on a transect line, you would walk either straight up or straight down a slope.
Understanding Contour Lines and Landforms
As a class, discuss how the following landforms would be indicated by contour lines on a topographic map.
- A cliff
- A flat meadow
- A mountain
- A river
Getting Started With the Map
Get acquainted with your map. Find the map legend. What part of the country is represented by your map?
Find the scale on the map. What distance is represented by an inch?
Locate a cliff, a mountain or hill, a river, and a meadow on your map. If you do not believe one of the these landforms appears on your map, explain why.
Types of Streams
- Intermittent stream:
- A stream that flows only during wet periods.
- Perennial stream:
- A stream that contains water year-round.
Locate as many first-order streams on your map as you can. How can you tell whether a stream is a first-order stream?
Are the streams you located intermittent or perennial? Show how each is represented on the map.
Thinking It Through
Where do you find first-order streams on your maps?
What are possible sources of water for first-order streams in mountains, low-lying swamp areas, desert areas, and areas close to the lower reaches of a river?
Going a Bit Further
Can you find places where water could flow as if in a stream, if it rained, but no stream has been indicated? These are the places where contours indicate a fold or a dip between slopes.
Why do you think no streams have been marked?