Contour cross-drainage lines form U-turns. What are these U-turns called?

Contour cross-drainage lines form U-turns. What are these U-turns called?

• A. Contour turnbacks
• B. Contour bends
• C. Contour inflections
• D. Contour loops

Answer: (A)

Contour turnbacks describe the distinctive U-shaped reversal that contour lines make as they wrap around a drainage valley. On a topographic map, contour lines show constant elevation, and when a stream cuts across terrain, the lines bend to accommodate the drainage path. This bending can create a noticeable backward turn or “turn back” around the drainage feature, giving that characteristic U shape. The term specifically captures the way the line reverses direction near cross-drainage, whereas the other options are too general: bends or inflections describe any curve, loops imply enclosed areas, and don’t pinpoint the drainage-driven U-turn behavior.

Contour turnbacks describe the distinctive U-shaped reversal that contour lines make as they wrap around a drainage valley. On a topographic map, contour lines show constant elevation, and when a stream cuts across terrain, the lines bend to accommodate the drainage path. This bending can create a noticeable backward turn or “turn back” around the drainage feature, giving that characteristic U shape. The term specifically captures the way the line reverses direction near cross-drainage, whereas the other options are too general: bends or inflections describe any curve, loops imply enclosed areas, and don’t pinpoint the drainage-driven U-turn behavior.