Water Erosion
suggested grade levels: 4- 6
view Idaho achievement standards for this lesson

Materials:

Large block of salt	Container for water
Runoff pan or bucket

* Note: This would be an excellent activity to accompany the hydrology section of the Digital Atlas. To get there: Click on Atlas Home, Mouse over Hydrology, then click on Ground & Surface Water Concepts. Encourage students to read through the surface hydrology pages and click on the links that show the pictures of flooding. This should stimulate their interests about the concept of erosion and will be a great precursor to the following activity.

Procedure:
1. Set up the block of salt and construct a drip system. A gallon container of water with a pinhole or series of pinholes suspended over the block of salt should work well. Have a runoff tray or bucket under the block..

2. Ask students to predict what will happen to the block over time.

3. Let water drip on the salt block for several days. Have a discussion on the block each day.

4. One day, collect a 30-ml sample of the runoff and compare it with 30 ml of tap water. Ask the class what is different about these two samples. What should happen if these samples are set out to dry?

5. Have discussion at end of week on erosion.
    a. How does this model simulate real life erosion?
    b. Can water erode rock over time?
    c. What can a flood do to the landscape?
    d. How can a river form a canyon?
    e. What other things besides water can erode the land?
    f. What can we do to prevent man-made erosion?
    g. Is erosion always bad?

Handouts/Activity links:
These are links to access the handouts and printable materials.
Ground & Surface Water Concepts

Related Lesson Topics:
Hydrology: Hydrology Topics