What is soil Erosion? Part 2
Lesson 11 of 18
Objective: SWBAT experiment with ways to slow or stop soil erosion.
I begin this lesson by showing this review video. The video sings about the definition of erosion in a way that students remember. Long after the video is over, many students continue to hum this song which reinforces the definition of erosion. Students have heard this song in a previous lesson.
Explore and Explain
In the first part of this lesson, yesterday, students explored erosion by observing what happened to soil as water was poured onto it. In today's lesson, students work with a small group to devise a plan in order to stop or slow erosion.
I start this lesson by telling students that they will explore erosion further by solving the central question from yesterday. “What can be used on the hillside to slow or stop the soil from eroding? Can it be stopped? To what extent can erosion be slowed or stopped?” Students will work together to design a plan centered on how they can stop or slow erosion on their hillside.
Just like yesterday, I show students a pile of dirt in a tin container. Again, I place little plastic figures like plastic people, tiny houses, model trees, etc., in different places around the mound of dirt. I remind student that yesterday when we poured water on top, we saw lots of erosion and movement of dirt. I ask students to brainstorm in their groups ways they could slow the erosion.
Students recreate their dirt hill from yesterday and make changes to it in order to slow erosion.
Listen in as these students talk about changes they'll make to their hill in order to slow erosion. (Note- when you hear students talk about grass or trees, I have grass seed available for students to use and plant)
These students are watering their dirt mound because they planted grass seed. Students will spend the next few weeks lightly watering their dirt mounds in order to grow the seeds planted. Most groups planted seeds. After several weeks have gone by, students will re-pour water on their dirt mounds and observe what happens. Most groups will find that their grass seed substantial slowed the amount of erosion on their hill.
To wrap up this lesson,I lead a brief whole class discussion and ask students to share their group's plan for slowing or stopping erosion. You can see two different plans below. You can see in the first example this group may have some misconception still about erosion. They seem to be focusing on the structures on the dirt hill rather than the dirt hill. The second photo shows a group thinking about adding things to the dirt to keep the dirt in place.
Last, I show an ending video that allows students to look for erosion in other examples. I ask students to look for erosion as they watch.