National Teachers Enhancement Network: Lesson Plan

Lesson Plan: Weathering and Erosion: Some Ways the Hydrosphere Affects the Geosphere
Subject: Earth and Space / Geosphere / Soil Erosion
Classtime: At least four 50 - minute class periods (can be adjusted as needed)
Grade Level: 4-6

Materials/Technology:

computers with Internet access
work sheets for each student
block of salt (mineral name: halite) or a mineral block. *Note: Salt and mineral blocks can be purchased at feed stores. (Mineral blocks may have more color, which may help student observations.)
suitable container for block of halite or salt and the run-off
simple drip system to demonstrate erosion
science journals

Safety, Handling, Disposal:
When using the Internet, close supervision is strongly recommended. Inappropriate sites are easily accessed, either by mistake or on purpose.

Learner Outcomes:
Students should be able to:

Explain the causes of erosion.
Describe the effects of erosion.
Devise a method of preventing erosion.
Model the before-and-after-effects of erosion.

Problem/Purpose:
Students will observe water erosion, investigate several Internet web sites to find answers to questions about erosion, and build a two-part model showing the before and after effects of erosion and/or erosion prevention.

Background/Inquiry:
Evidence of the effects of weathering and erosion are dramatically evident in places such as the Grand Canyon. However, though dramatic, the processes that formed these canyons took millions of years. Students need to understand that the Earth is dynamic—in a constantly changing state. All natural features on the Earth were formed over time and are still being formed today. According to Izolda Takhtenberg at the Goddard Space Flight Center, it can take as long as five hundred years for one inch of usable soil to form and just seconds for that soil to be eroded away. Another USDA source says it takes as much as one thousand years for one inch of soil to form.

Vocabulary List: Here.

Hypothesis:
Pose this hypothetical question: If water pushes against an object for an extended period of time, what would happen? After demonstrating the erosion process in the classroom, have students develop hypotheses that relate the process of erosion to real life scenarios.

Procedure:

Advanced teacher prep -
Purchase a block of salt. Devise a simple constant drip system* to simulate erosion in the classroom. Make a system that can provide a steady drip or stream over a period of days. This allows students to observe the results (erosion) of the water dripping onto the salt over time—much like the erosion that takes place in the real world of nature.

*A simple drip system might consist of a plastic gallon milk jug with a small hole in the bottom suspended above the block.

Student procedure:

1. A week prior to beginning your official study of erosion set up a block of salt in the classroom. Make this demonstration model easily accessible to students. Construct the simple drip system and begin the process. Let it run.

2. On the first day that the demonstration model is operating, take some time in science class to draw students’ attention to it. Write the word “erosion” on the board. Give students five minutes to write in their science journals a definition of what they think erosion is and make predictions on how the block will look on day 2, day 3, and through the rest of the week. Have them use drawings and/or writing to describe what they think.

3. On day 2, catch some of the water run-off for students to analyze. Take 25ml of the run-off and 25ml of the drip water, place in glass containers and allow both to evaporate. Have students predict what will happen in the two different containers and record predictions in science journals.

4. Students observe the model daily. Give them five minutes of journal time to write down what they see taking place on the salt block and in the containers with the two different waters. Require students to compare their observations to the predictions that they made on day 1 and day 2 as part of the writing process.

5. After the week is through and students begin to formally study erosion, discuss with students what they think erosion is. Share journal entries and compare predictions with what really happened.

6. Tell students that they have been observing erosion on a salt block over the past week. Have students write down what they now think the correct definition of erosion is based on their recorded observations. Students should have observed that over time the dripping water has washed away a noticeable amount of the material (removal of material equals erosion).

7. Have students hypothesize how this process (erosion) is related to real-life situations.

8. Have groups of students research the questions found on Worksheet 1 using the given web sites. Be sure to review acceptable-use rules before sending them to the Internet.

9. Have students complete the worksheets provided.

10. Pass out “Soil and Erosion Model Project” sheet. Review with students.

11. Have students create models showing the before-and-after-effects of erosion with or without erosion prevention methods. Students should complete this task at home over a period of two or three nights.

12. Have students present their models to the class, explaining the different elements and how they show the before and after of their chosen situation.

13. It is important to have a discussion to close this activity by summing up what the students have learned about erosion and soil conservation.

STUDENT WORKSHEET #1

NAME: ____________________

Soil and Erosion Worksheet #1

Use the Internet to find answers to the following questions.

The sites below may help:

*ATTENTION:

Write the URL where you found the answer.

How long does it take one inch of soil to form? Why?

URL:

How much usable soil is there compared to the surface of the Earth? [Hint: Work your way through the pages comparing the earth to an apple.]

URL:

What are the three primary types of erosion that farmers must deal with?

URL:

Soil can be eroded in a very short time (minutes in the case of high winds, floods, etc.). Describe at least four ways farmers prevent erosion in their fields.

URL:

Describe the formation of the Grand Canyon. Be complete in your description.

URL:

How long do geologists think it took to form the Grand Canyon? Why?

URL:

Define the term “soil degradation”.

URL:

What effects can soil degradation have on agriculture and water quality?

URL:
PROJECT HANDOUT

NAME: ____________________

Soil and Erosion-- Model Project

Think about situations where erosion may occur. Sometimes erosion is destructive, as when a farmer's field is blown/washed away or a beach erodes, taking houses with it. Sometimes erosion creates beautiful landscapes as in the Grand Canyon, Canyonlands National Parks and Arches National Park. Fertile river valleys often result from the deposition of eroded materials.

Assignment:

Build a two-part model. In the first part of the model show a situation in which erosion is an issue. This may be before/after erosion or before/after human involvement. The second part of the model will show a change in the situation. Both sections may include the effectiveness (or lack of effectiveness) of erosion prevention methods.

For example:

Part one model shows a gullied hillside. Part two shows the same hillside after trees have been planted.

Use the concepts learned from your investigation of different web sites (Worksheet #1) to support the accuracy of your two-part model.

Project Grading:

Statement of Model

The Model

Present your models to the class. Explain the situation you have chosen to model and how your models show the before and after situations.

Conclusions:
Erosion is a common part of the changing of the Earth’s surface. Erosion happens in many different ways resulting in many varied situations.

Assessments:

Utilize the rubric to grade the projects. It might be best to have the students grade each other’s projects. The rubric is clear and easy to follow.

Reflections:
Share your thoughts on this lesson with the NTEN team.

Please send an e-mail to Patti Harrison.

Extensions: Take students on a short hike in the area around the school noting instances of erosion that the students see in the area.

References/Resources:

Standard 4.1 from the "Colorado Model Content for Standards in Science
National Science Content Standard D
Kenyon College Gambier, Ohio 43050 (740)-427-5000 Educational activities based around soil.
USGS Web page “The effects of urbanization on water quality: Erosion and sedimentation.”
The Importance of Land Degradation, from University of Oxford Environmental Change Unit: Land Degradation and Rehabilitation Programme
Agriculture and the Environment: State of the Land from the Natural Resources Conservation Service, The United States Department of Agriculture
Skworm answers questions about soil. From the Natural Resources Conservation Service, The United States Department of Agriculture http://www.nrcs.usda.gov/feature/education/squirm/skworm.html

Credits
Contributing Teacher: Tara Klima
NTEN Course: K-14 Earth and Soil Science
Instructor: Jerry Nelson
Developing Team:
T.L. Buck Buchanan, Patti Harrison, Don Samuelson, John Usher, Don Wilson
HTML Programmers: Tyson N. Trebesch, Ryan Huddleston, Andy Tomascak, Ching-Kwong Chia

Up to Top