Certified Storm Water Operator Practice Exam

What is the contour interval?

1. The distance between two landforms

2. The vertical distance between adjacent contour lines

3. The horizontal distance between features

4. The total elevation change on a map

The correct answer is: The vertical distance between adjacent contour lines

The contour interval refers specifically to the vertical distance between adjacent contour lines. In topographic maps, contour lines represent points of equal elevation. As you read the map, each contour line indicates a specific elevation above a reference point, typically sea level. The contour interval provides critical information about the steepness and grading of the terrain; closer contour lines indicate steeper slopes, while wider intervals suggest a gentler gradient. Understanding the contour interval is essential for interpreting the landscape's topology and for tasks such as construction, land use planning, and environmental assessments. The other options refer to different concepts; for example, the distance between two landforms relates to horizontal spacing rather than elevation differences, while the total elevation change on a map encompasses more than just the adjacent lines. Thus, the definition and function of the contour interval are precisely captured by the correct answer.