2-ESS2-1: Designs That Slow Wind and Water Erosion
Also called NGSS 2-ESS2-1 · Topic: Earth's Systems: Processes that Shape the Earth · Earth and Space Science
The Official Wording
Compare multiple solutions designed to slow or prevent wind or water from changing the shape of the land.
Clarification statement: Examples of solutions could include different designs of dikes and windbreaks to hold back wind and water, and different designs for using shrubs, grass, and trees to hold back the land.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 2-ESS2-1 Means in Plain English
Second graders compare different designs that keep wind or water from reshaping land. They look at real solutions, like rows of trees that block wind, walls that hold back water, or grass that keeps soil in place, and test models of their own.
The focus is comparing how well each design works, not explaining every cause of erosion. It pairs with fast and slow Earth changes (2-ESS1-1) and leads to designing ways to reduce the impact of natural hazards (4-ESS3-2).
2-ESS2-1 I Can Statements
- I can explain how wind and water change the land.
- I can compare two or more designs that slow down erosion.
- I can use test results to choose the best design.
2-ESS2-1 Worked Example
A windbreak test in a shallow tray with a small fan and a mound of sand.
What kind of windbreak keeps a sand mound from blowing away?
Set It Up: A shallow tray with a mound of dry sand, a small battery fan, craft sticks, a strip of cardboard, a row of small plastic plants and a ruler.
- Run the fan on low for 30 seconds, 20 cm from the mound, with no windbreak.Sand spreads 12 cm past the mound
- Rebuild the mound and stand a craft-stick fence with gaps in front of it.Sand spreads 5 cm
- Try a solid cardboard wall in the same spot.Sand spreads 3 cm, some swirls over the top
- Try the row of small plastic plants.Sand spreads 6 cm
- Compare the distances, then talk about cost and how each one looks.Wall stops most, fence nearly as well
Every windbreak cut how far the sand blew, and the solid wall and the fence worked best.
Why it works: A windbreak slows the wind before it reaches the sand, and slower wind can carry less sand away.
Common Mistakes with 2-ESS2-1
Changing the test along the way
Moving the fan closer for the cardboard wall
Try this: Keep the fan the same distance and speed for every design, so the windbreak is the only thing that changes.
Expecting a perfect fix
“The fence failed because some sand still moved”
Try this: Most real solutions only slow erosion down. Compare how much each design reduced the spread, not whether it stopped it.
Judging by one try
Testing each windbreak once
Try this: Run each design three times, rebuilding the mound to the same size each time, and compare the usual result.
Where 2-ESS2-1 Fits
Practice 2-ESS2-1
Quick Check
- Why do farmers plant rows of trees along the edge of a field?
- How does grass help keep a hillside from washing away?
- Two windbreaks both cut the sand spread in half. How could you choose?