Erosion - Science Fair Project

Earth Science Unit Study
Week 33:  What kind of ground erodes the fastest?

Several types of soil were tested by pouring water on equal amounts of soil to determine which erodes the fastest. The following is my 10 year old son's science fair project.

Problem
One type of erosion is when ground gets broken off by a river or a stream. This is sometimes bad because it can change the rivers course by clogging it up. Sometimes erosion happens right under houses. If that happens you should pack up your belongings and leave. If you don’t have time, pack up your valuables and leave. Erosion is bad for farmers because it washes away their lose ground. Erosion happens fast or slow on different kinds of ground.

Hypothesis
My hypothesis is sand will erode fastest because it is only little rocks. Mud and leaves will erode the least because the leaves will slow it down.

Materials
sand, mud and leaves, compost, shovel, watering can with water, scale

Procedure
First I got a scale, then I got one cup of compost, sand, mud and leaves. I weight the compost, sand and mud. Then I got a watering can. After that I got a shovel for a hill. I poured water five seconds on each kind of soil then I waited for the soil to dry. After it dried I weighed it to see how much eroded away.

Results

Conclusion
It turned out I was partially right. Sand eroded the most. Sand lost one hundred eighty grams. Mud and leaves lost seventy grams. Compost lost sixty two grams. I was surprised that mud and leaves eroded the second most. I thought mud and leaves would erode least. The little sticks in the compost must have slowed the erosion down more than the leaves.

The results could be different if the amount of erosion was calculated based on volume instead of weight. Other ground coverings may erode more or less than the tested materials. Maybe next time I could test clay, rock, smaller rocks, wood chips, dirt and grass, and plastic like the type at Donnelly Park.