Weathering+&+Erosion+K-2

Lesson Objectives
 * Define and describe weathering and erosion.
 * Recognize ways that plants can help reduce erosion.
 * Model erosion.



Engage: Activate Prior Knowledge; Generate Interest

**Activate Prior Knowledge** Start the lesson by asking students to visualize a sand pile on the playground. You may wish to have a volunteer draw one on the board. Label the drawing “Before.” Then allow students to imagine that a great storm, with wind and rain, occurs. Ask them to describe what they think will happen to the sand pile. Allow another volunteer to draw the “After” sand pile. Explain that what happens to a sand pile in a rainstorm is an example of erosion. Erosion is a process that shapes the surface of Earth. It is one of the processes they will learn about in this lesson.

Next, share a brief demonstration with the class. Have three large clear plastic bins prepared at the front of the room and a full bucket of water. Direct your students’ attention to the first bin, which contains a pile of brown dirt. Slowly pour water over the dirt, and allow students to witness what happens to the pile (it washes away). Next, direct their attention to the second bin, a medium-sized pile of sand. Pour water over the sand, and allow students to witness what happens to the sand. Repeat the procedure with the third bin, which contains a small pile of rocks or gravel. After all three materials have been exposed to “erosion,” ask students to draw conclusions from the demonstration. Ask them what effect water has on soil, sand, and rocks. This readies them to learn more about weathering and erosion.

**Stimulate Interest** Use the video segment [|Weathering and Erosion] (1:52) to introduce the processes of weathering and erosion. After students watch the video, ask volunteers to define or describe weathering and erosion. Point out that weathering and erosion can have creative and destructive effects. Explain that students will learn more about the creative and destructive effects of erosion and weathering.

Explore: Allowing Students to Experience Content

Post the Essential Questions that constitute what students will be learning. Students may read them to themselves or you may wish to read the questions aloud together.
 * What is weathering?
 * What is erosion?
 * How can plants help reduce erosion?

Write the words weathering and erosion as headings of a two-column chart on the board. Have students copy these two words onto two pages in their science notebooks—one word as the heading on a page. Explain to the students that they will be doing some activities to explore what weathering means and what erosion means.

As a class, explore the Fun-damental [|Our Changing Earth] opening only the Earth's Changing Surface section. (Stop exploring after the weathering, erosion, deposition section, do not explore volcanoes and earthquakes right now) As you explore weathering and erosion by wind, water and ice, add information to your T-chart on the board and in journals.



Tell students that they will be watching other video segments—this time focusing on erosion. Explain that they will need to look for things that cause erosion and the effects of erosion. If necessary, review cause and effect. As they watch it, students can draw pictures or write words on the erosion page of their science notebooks to show the causes and effects of erosion. Have students view [|Erosion: Wind, Water, and Ice] (3:33) and [|How Does Water Shape the Land?] (:56).

After students have watched the video segments, ask them to share what they drew or wrote with a partner. Ask each pair to draw two pictures—one showing a cause of erosion, and one showing an effect of erosion—that they learned about in the videos. When complete, allow time for pairs to share their causes and effects with the class. As you monitor student progress, be sure to record anecdotal notes on the Teacher Observation sheet located in the Evaluate Tab.

Explain: Firm Up Understanding; Allow Students to Explain What They Know

Explain to the students that you are going to play two animations. They are to watch both animations and decide which one shows weathering and which one shows erosion. Play the [|erosion] animation first (students by this point are used to weathering coming first). Then play the [|weathering] animation. Write the words CLAIM and EVIDENCE on the board. Ask students which animation showed weathering, animation A or B. Under the word CLAIM write the B. Ask the students to explain how they knew that was the weathering animation. Write all observations cited under EVIDENCE. Repeat this process for the erosion animation.



Explore: Allowing Students to Experience Content

Read together as a class the reading passage [|Plants and Erosion] there is also an [|e-book version] that can be used with struggling readers. Ask students to consider the following questions after reading. Have them discuss the questions in pairs and share ideas. Students should record answers in their journals.



Explain: Firm Up Understanding; Allow Students to Explain What They Know

Have students draw pictures of two hills, one with and one without plants. What happens on each hill when it rains? When it is windy? When snow or ice runs down the hill? Have students draw pictures of each scenario. Have students share their pictures with the class and explain them.

Elaborate: Allow Students to Apply What They Know

Have students work in small groups to complete the [|Hands-On Activity: Let It Rain]. Students will work together to design and construct a model riverbank. They will then use watering cans to test the effects of erosion on the riverbank’s soil and plant life.

Estimated time to complete: 50 minutes

Project Ideas: To help your students apply their understanding of how weathering and erosion affect people, you may wish to have your students complete some or all of the following projects. The time required to complete each project will vary; some may require students to work outside the classroom.
 * Students can look for and draw or photograph examples of weathering and erosion in their own yards, parks, or neighborhoods. Allow students time to share their examples with the class.
 * Students can look at photographs of landforms and discuss how each is formed, broken down, or otherwise changed by weathering and erosion. Students can use their ideas to make posters about weathering and erosion.
 * Students can research and/or participate in community erosion control measures, such as planting native plants on river and stream banks.

Evaluate: Check for Understanding

Break the class into groups of four to five students each, then share images of eroded rivers, rocks, hills, and soil (for images, search Discovery Education Science Techbook) and ask the groups to decide if the form was eroded by wind or water and to explain their reasoning.