Erosion Basics
Water that flows over the land surface instead of soaking into the ground.
Runoff
Erosion that removes a thin, even layer of soil from a large area.
Sheet Erosion
The practice of preventing soil erosion and maintaining healthy soil.
Soil Conservation
The uppermost, nutrient-rich layer of soil where many plants grow.
Topsoil
The factor that a scientist purposely changes during an experiment.
Independent Variable
The process that breaks rocks into smaller pieces.
Weathering
Erosion that forms small channels as runoff concentrates and flows downhill.
Protective material such as straw, leaves, or wood chips placed over soil to reduce raindrop impact.
Mulch
Planting rows across a slope instead of straight up and down a hill.
Contour Farming
The factor that a scientist measures or observes as the result of an experiment.
Dependent Variable
After a heavy rain, soil from a bare hillside is carried downhill and deposited near the bottom. What process moved the soil?
Erosion
After several heavy storms, runoff has carved large, deep channels into an exposed hillside. What type of erosion has occurred?
Gully Erosion
A farmer plants grasses and other plants specifically between growing seasons to protect exposed soil and improve its condition. What conservation technique is being used?
Cover Crops
A farmer leaves the soil unplowed and plants directly into the previous crop remains. What farming method is being used?
No-Till Farming
Students test different methods for preventing erosion. One tray has bare soil and receives no erosion treatment so the other trays can be compared to it. What is this tray?
Control
Two fields receive the same amount of rain. Water quickly soaks into Field A, while much more water flows across Field B. What process is occurring more effectively in Field A?
Infiltration
Muddy water leaves a construction site and carries soil particles into a nearby stream. What process describes the movement of that sediment from one location to another?
Sediment Transport
Trees, shrubs, and grasses are planted along the edge of a stream to slow runoff and keep eroded soil from entering the water. What is this protected area called?
Riparian Buffer
A farmer changes a steep hillside into a series of flat, step-like areas. How does this help reduce erosion? Name the conservation technique.
Terracing
Students test mulch, grass, and terracing using identical trays. They give every tray 500 mL of water, use the same soil amount, and keep the same slope. What are these conditions called?
Constants
During a storm, a steep bare hillside loses much more soil than a flatter grassy hillside. Identify two factors from the word bank that explain why the steep bare hillside experiences more erosion.
Slope + Vegetation Cover
After rain hits a freshly plowed field, tiny soil particles are loosened before runoff begins carrying them away. What process caused the soil particles to break apart?
Raindrop Impact
A construction crew installs a temporary fabric barrier downhill from exposed soil. After a storm, muddy sediment collects behind the barrier instead of entering a storm drain. What conservation method did they use?
Silt Fence
After harvesting corn, a farmer leaves stalks and leaves covering the field instead of removing them. This leftover material protects the soil from rain and runoff. What is it called?
Crop Residue
Rainwater flows across a fertilized lawn, picks up chemicals, and carries them into a nearby stream. What term describes the harmful substances carried into the water?
Pollutants, Fertilizer