CST Level 1 Land Surveyor Certification Practice

Which of the following statements is true about contour lines on a topographic map?

1. Under some circumstances, a single contour line may split into two.

2. Under some circumstances, two contour lines may join into one.

3. A contour line cannot end within a map; it must either close on itself or terminate at the neat line of the map.

4. One contour line never crosses another.

The correct answer is: One contour line never crosses another.

The statement that one contour line never crosses another is true because contour lines represent locations of equal elevation on a topographic map. When two contour lines were to cross, it would imply that there are two different elevation values at the same location, which contradicts the fundamental principle of what contour lines represent. Each contour line must maintain a unique elevation to avoid confusion. If they were to intersect, it would create a scenario that doesn't exist in real terrain; this could lead to misinterpretation of the landscape and confuse the user regarding altitude changes. Therefore, this principle is essential in ensuring the clarity and accuracy of topographic representation. The other statements do not align with standard practices in mapping: a single contour line cannot split as that would suggest different elevations at one point, two lines joining would imply convergence of elevations, which can happen only under specific circumstances such as at a cliff edge and contour lines should indeed terminate at map edges or loop back upon themselves, rather than just stopping.