Erosion adversely alters both the land and water.
Erosion is an earth science principle related to how the wind, rain and other weather-related activities can eat away at soil levels and shorelines. Erosion can also contribute to sediment pollution in waterways. Erosion is a concern especially in bay and ocean-side communities. Engaging in hands-on activities with your middle school students will allow them to visualize how erosion affects the world.
Erosion Investigation
This experiment, created by Melissa Breuer for the Miami University of Ohio, aims to help students understand how erosion works in order to fully grasp its effects. First, discuss the principles of erosion with the class. Explain the effects of strong storm winds, high waves and water on beaches, river banks and other surfaces. Then, gather a bucket of dirt or topsoil and set up a folding table outdoors in a location with access to a garden hose and an electrical outlet. Set up a fan near the table. Dump the soil on the tabletop. Ask students what they think will happen when you turn on the hose and fan. Ask the students whether the water or the wind will have a stronger effect. Finally, have the students stand back to avoid getting dirty. Turn on the hose and fan as students watch the soil wash away.
"Can't See the Water for the Dirt" Project
The Bay Trippers' website recommends this projects to help students understand how erosion deposits dirt into rivers, streams, lakes and other waterways, thus affecting aquatic plants and animals. First, discuss how the animals and plants in bays need sunlight to survive, yet erosion interrupts this by causing excess dirt to wash into bays. Next, divide your students into small groups and provide each group with two glass jars, two plastic aquarium plants, a spoonful of dried beans and elbow macaroni, and a spoonful of dirt. Have each group fill the jars with warm water. Direct students to add one plant, some beans and macaroni to each jar to represent the plants and animals in a bay. Have the groups add the dirt to one of the jars and shake it, and observe what happens when the dirt mixes with the water. Have students predict which of the example bays would allow more sunlight to reach the plants and animals.
Soil and Water Testing
An alternative investigation you can pursue with your students involves collecting local soil and water samples and testing them for the presence of pesticides. As erosion occurs and soil washes into water, the water can become contaminated with pesticides used to treat gardens and farmland. Bay Link suggests that you can, if resources allow, set up a field trip to local farmland or garden areas to collect soil samples. Send the soil samples to local offices of the Department of Agriculture, or the horticulture department of your local university, for analysis. Be sure to include the location of the sample and the date taken with the sample. For the second part of the project, take students to local waterways to collect and document water samples. Display the samples in your classroom. Observe the different amounts of sediment in each sample and facilitate a class disscussion on the different effects of erosion and sediment pollution on the water's ecosystem. Finally, analyze the results of the soil analysis and discuss how the presence of pesticides would affect the local water supplies.
Rock Erosion Project
In addition to pushing soil, sediment and chemicals into the water, erosion also affects the land. According to Tera M. Hoover, writing for the University of Southern California, the following experiment can explain how a severe storm, or the constant movement of water, can eat away at rock, soil and shorelines. Place a water pump inside a large plastic tub. Place a paint tray in the tub. Select several different types of rock and record the weight of each. Set the rock samples in the paint tray. Turn on the water pump so that it flows over the rocks. Reweigh the rocks after 1, 5, 10 and 14 days. Discuss how the water changed the weight of the rocks in different ways. Note that soft rocks such as sandstone or soapstone will erode more quickly than will a dense rock such as granite.
Tags: plants animals, each group, First discuss, help students, help students understand, hose students
