What does the vertical difference between adjacent contour lines represent?

The vertical difference between adjacent contour lines represents a contour interval, which is a key concept in topographic mapping. The contour interval is the constant distance in elevation between one contour line and the next on a map, indicating the change in elevation over that horizontal distance.

When you examine a topographic map, each contour line represents a specific elevation, and the difference between those lines allows you to understand how steep or gradual the terrain is. A smaller contour interval indicates a more detailed representation of changes in terrain, while a larger contour interval suggests a broader overview where minor changes may not be represented.

This concept is essential for various applications in geography, land surveying, and environmental studies, as it allows for the visualization of elevation changes across a landscape, which is crucial for planning and analysis purposes.