In the described landscape-model erosion activity, which scientific question can be investigated most directly?

• A. What are some factors that affect erosion?
• B. How does drought influence plant growth?
• C. What determines the color of soil?
• D. How does water chemistry affect plant uptake?

Answer: (A)

At the heart of this activity is how erosion responds to different conditions. Erosion can be studied directly by varying clear, controllable factors—like slope angle, how much water flows over the surface, and how much ground cover or vegetation is present—and then measuring how much soil is displaced or how quickly rills form. Because you can manipulate these variables and observe the resulting soil loss in the landscape model, the question about factors that affect erosion is the one you can investigate most directly. The other options shift focus to plant growth under drought, a property like soil color, or how water chemistry affects plants, which involve different processes and aren’t testing the erosion mechanism as directly.