Which contour lines carry the elevation numbers on the map?

Which contour lines carry the elevation numbers on the map?

• A. Index contour lines
• B. All contour lines
• C. Only water lines
• D. Road lines

Answer: (A)

Contour lines on a topographic map show lines of equal elevation. To keep the map readable, the elevation numbers are placed only on the darker, bolder lines called the index contour lines. These are labeled at regular intervals (often every fifth contour line), providing the height at those lines so you can estimate elevations across the map. The lighter, intermediate contour lines carry no numbers but still represent the same elevation steps between lines. Water lines and road lines aren’t contour lines, so they don’t carry elevation numbers. So, the lines that carry the elevation numbers are the index contour lines.

Contour lines on a topographic map show lines of equal elevation. To keep the map readable, the elevation numbers are placed only on the darker, bolder lines called the index contour lines. These are labeled at regular intervals (often every fifth contour line), providing the height at those lines so you can estimate elevations across the map. The lighter, intermediate contour lines carry no numbers but still represent the same elevation steps between lines. Water lines and road lines aren’t contour lines, so they don’t carry elevation numbers. So, the lines that carry the elevation numbers are the index contour lines.