After reading the question, students are encouraged to formulate hypotheses. Teachers who participate in the challenge also have the opportunity to gain valuable experience in teaching inquiry-based science because each new challenge helps to reinforce basic science concepts. For personal advice and support from Steve, join the Hands-On Science discussion in the Teacher Center. In this experiment we explore the changing surface of the Earth and discover the effects of erosion. By setting up a simple model of a stream, students see how slope, soil texture, and cover affect the amount of erosion that occurs on soil.
Erosion is a natural process.
Any time water flows over the land surface, it works to remove soil particles from the upstream end and deposits them in low-lying areas, generally causing the surface to level out. Three key factors help to control how much erosion will occur. The steeper the slope, the more kinetic energy a stream will have and the better equipped it will be to remove loose particles. All the energy to do the work is supplied by gravity. In many cases, fast flowing streams not only pick up soil grains, but they can transport larger rocks by rolling them along the bottom.