May contours intersect?

May contours intersect?

• A. Yes
• B. No
• C. Only at the headwaters
• D. Only in flat regions

Answer: (B)

Contour lines show all points at the same height on a map. Since every ground point has a single elevation, you can’t have two different elevations at the same spot. If two contour lines crossed, that would imply that one location has two different heights, which isn’t possible for a real surface. So intersections don’t occur on standard topographic maps. In steep areas the lines run very close together, in flat areas they’re far apart or absent, but never cross. Heads up: headwaters or flat regions don’t create crossings either; they just affect how the lines appear nearby.