After teaching a lesson on erosion, take your students out to the area around the school to search for areas that have been affected by erosion. Take your measuring tape or ruler with you to measure the amount of erosion you find. If you cannot find any evidence, take a garden hose, a bucket of soil and a fan into the parking lot. Turn the fan on and pour the dirt in front of the fan. Show the students what wind alone does to the soil. Then turn the fan off, and pour the water over the dirt. Have the students measure how much soil is removed after a specified number of minutes. Bring a camera to get photographic evidence of erosion.
Place sugar cubes in a 13-by-9-inch pan. Have your students make educated guesses about what will happen when you pour water over the sugar cubes. Have them guess how much of the sugar will be removed by plain water and by carbonated water. Now pour the water over the cubes. Explain what happened and why the cubes sizes decreased. Add gravel to the sugar cubes and see if the reaction is different. Teach the students about how water erodes rocks and caves.
Teach your students about acid rain and its causes and effects. Have your students predict what will happen if you pour acid-water over chalk or a penny. Add vinegar to water and pour it over chalk, or limestone. Test chalk dust and whole pieces of chalk to determine how erosion occurs on dust versus solid surfaces or rocks. Pour it over a copper penny. Have the students identify the reaction after 20 minutes and then again after 24 hours.
Take your students to different water sources, such as lakes, ponds, streams and rivers. Take samples of the water from each location. Samples are best taken during a run-off time or during the rainy season where there is more water flowing. Have the students look at the samples and discuss what types of sediments they think are in each sample. Take the samples to your local geology lab, university lab or government extension office for analysis. Discuss the analysis with your students when it comes back from the office.