Do contour U-turns point upstream or downstream?

Do contour U-turns point upstream or downstream?

• A. Upstream
• B. Downstream
• C. They have no fixed direction
• D. They point toward the drainage divide

Answer: (A)

Contour lines show equal elevation and how the land rises or falls. When a contour line makes a U-shaped bend near a valley or stream, the bend wraps around higher ground, so the interior of the curve sits toward higher terrain that lies upstream. Since water flows downhill, the upstream direction is toward higher ground, where the land rises to the drainage divide. In short, contour U-turns indicate the direction toward that higher ground, i.e., upstream.

Contour lines show equal elevation and how the land rises or falls. When a contour line makes a U-shaped bend near a valley or stream, the bend wraps around higher ground, so the interior of the curve sits toward higher terrain that lies upstream. Since water flows downhill, the upstream direction is toward higher ground, where the land rises to the drainage divide. In short, contour U-turns indicate the direction toward that higher ground, i.e., upstream.