View All Posts

Apr 03

Erosion Lesson and "Splash Zone" Activity

Posted on April 3, 2020 at 10:22 AM by Rebecca Crust

What is Erosion?
In the previous lessons in this soil series we covered why soil is important and what soil is made of. The purpose of this lesson is to explore human impacts on soil.

You may already know the different ways that humans interact with soil. We grow our food in it, build our homes on it, and admire the nature that comes from it. However, because our lives are so intertwined with soil, humans have the power to both sustain and mistreat our soil.

One way that we can sustain our soils is by taking actions to prevent erosion. Erosion is when water or air displaces soil. Over long spans of time erosion can create amazing natural structures, for example the Grand Canyon or the Tsingy de Bemaraha.

sonaal-bangera-Grand Canyon
Photo by Sonaal Bangera
depositphotos_34556559-stock-photo-tsingy-de-bemaraha-madagascar
Photo by Oscar Espinosa

Sometimes erosion can be harmful, for example when it strips farmland of topsoil and nutrients. We like to point to the historical event known as the Dust Bowl as an example of what happens when we don’t take measures to preserve our soils. During the 1930’s, the American plains and mid-west regions suffered serve dust storms. A lot of factors contributed to the Dust Bowl including over-tilling, removal of native plants, drought, and growing monocultures of shallow rooted crops like corn and wheat.

Dust Bowl Image 3
Dust Bowl Image 5
There are things we can do today to prevent erosion, even as kids!
  • Grow a garden
  • Plant native plants in your yard or neighborhood
  • Use sustainable farming methods
  • Use organic compost as opposed to nitrogen-based fertilizers
  • Avoid using pesticides
  • Reduce, reuse, and recycle! (the less we use, the fewer resources we need to extract)

Splash Zone Activity

Materials : Paper target, pinch of soil, water dropper

This activity models how fast erosion can happen on loose soil. To set up, print out the target linked here, or draw a similar design on a loose piece of paper. (We at the district use a laminated sheet so that we can reuse it, if you have need to do the activity multiple times, then putting wax paper over the target works well too.

Once you have the target set up on a flat surface, add a pinch of loose soil (ideally dry) to the center of the target. Hold a water dropper about 1 foot above the target and drop water one drop at a time onto the soil. Count how many drops it takes for the soil to move to the furthest zone. It shouldn’t take many!

Reflect by comparing this to a natural system. When soil is not held in place by plants and then is hit by rain, it moves at a similar fast pace.