Mary Ann Cavanaugh, Grade 4 Teacher
Students will be able to identify erosion and explain the causes of erosion.
Materials: potted plant
disposable aluminum pans
container for water
Related URLs: Wind Erosion
abe.www.ecn.purdue.edu/~agen521/epadir/erosion/wind_erosion.html Water Erosion
abe.www.ecn.purdue.edu/~agen521/epadir/erosion/water_erosion.html Glacial Erosion
Class demonstration (20 minutes):
Outside activity (25 minutes):
- Take a potted plant out of the pot, with soil intact. Discuss how the roots of the plant help to hold the soil in place. Ask what would happen if the plant was not in a pot, but in the ground and water keep running over it. Introduce the term erosion and discuss how wind, water, and ice can cause erosion. Ask students if and where they have ever seen the effects of erosion.
- Explain that the class is going to go out to the playground to examine the effects of erosion on our playground and surrounding school property. Ask students to remember how plants hold soil and to pay special attention to the placement of trees and shrubs on the school grounds. Students will be asked to take a pencil and notebook to write and draw evidence of erosion on the school property.
Closing discussion (15 minutes):
- As a class, point out evidence of erosion on the school grounds. Some good examples are often near drains, drain pipes, and at the edges of the blacktop.
- Then have the students pair up with a partner to examine the rest of the area to look for other signs of erosion. Don't forget to set boundaries where students may explore.
- When students find examples of erosion, they are to describe it in their journals and draw a labeled rough sketch of the erosion.
- After students are back in the room, ask them to share what they have written in their journals about the effects of erosion on the playground and school property.
- Ask if anyone noticed the placement of trees and shrubs. Ask the students if the trees and shrubs were placed in particular areas to help stop the effects of erosion.
Classroom review (10 minutes)
Computer Activity (20 minutes):
- Review the term erosion and how plants help stop erosion.
- Discuss the forms of erosion that were witnessed on the playground and school property. Explain that most of the erosion that was witnessed on the playground was caused by water.
Follow-Up/Extension Activity (20 minutes):
- Have students view the effects of wind, water, and ice on soil and rocks by going to these sites. Instruct students to read the information and view the pictures.
- Provide each pair of students with a disposable aluminum baking tray, enough soil to fill the tray, water, small container, newspapers and some rocks. Cover each working area with newspapers.
- Instruct students to fill their tray with soil, patting down to firm in place. Position rocks in the soil so that they can not move about freely.
- Place the narrow side of the tray filled with soil and rocks on a book, so as to place the tray on a slant.
- Next have one of the students pour little drops of water, starting at the highest part of the tray, so the water can run down the soil.
- Ask students to notice if any changes are taking place in their trays. See if the soil or rocks are moving out of position.
- Direct the other student to pour larger amounts of water at the highest part of the tray. Again, ask the students to describe what changes are taking place in the tray. Are they seeing signs of erosion?
My students love this lesson. They especially enjoy exploring the school grounds for signs of erosion. The hands on activity is another highlight of this lesson.