Do contours on opposite sides of a stream have the same value or different values? Why?

Do contours on opposite sides of a stream have the same value or different values? Why?

• A. Same value; contours are paired across drains (last contour crossed descending one side of stream valley is first one crossed ascending other side)
• B. Different values; streams cause offset in contour elevations
• C. Same value but not paired
• D. Depends on the slope of the terrain

Answer: (A)

Contours are lines of equal ground elevation, and they form continuous paths across the landscape. In a stream valley, the land on either side that sits at the same height belongs to the same contour line, so a given elevation value appears on both banks. As you move down one side and reach the valley and then continue up the other side, the same contour line is followed through the valley: the last contour you cross descending one side is the first you encounter ascending the other side. This pairing shows that the elevation value is the same on both sides of the drain. The weathering of the valley or the presence of the stream doesn’t create a different contour value there; slope affects spacing, not the fact that the same contour value stretches across the valley.

Contours are lines of equal ground elevation, and they form continuous paths across the landscape. In a stream valley, the land on either side that sits at the same height belongs to the same contour line, so a given elevation value appears on both banks. As you move down one side and reach the valley and then continue up the other side, the same contour line is followed through the valley: the last contour you cross descending one side is the first you encounter ascending the other side. This pairing shows that the elevation value is the same on both sides of the drain. The weathering of the valley or the presence of the stream doesn’t create a different contour value there; slope affects spacing, not the fact that the same contour value stretches across the valley.