1) What is the effect of slope on soil erosion (the washing away of the soil) by water? Design and carry out an experiment to compare at least 4 different inclines to see how much soil is lost from each one when rain hits the soil. (You can make simulated rainfall.)
2) What is the effect of soil type on how fast water flows through the soil? Design and carry out an experiment to compare at least three types of soil (e.g., sand, potting soil, clay soil) to see how fast a given amount of water will drain through each one.
3) In what order do materials settle in water? Design and carry out an experiment to determine the order in which different sized materials (e.g., sand, gravel, topsoil) settle out in water after they have been mixed up.