What does it signify when contour lines are close together on a map?

When contour lines are close together on a map, it indicates a steep slope. Contour lines represent elevation changes, and when they are spaced closely, it means that there is a rapid change in elevation over a short horizontal distance. This steepness can be visualized as a mountain or hill that rises quickly, differentiating it from gentle slopes where contour lines are spaced farther apart. The proximity of these lines reflects the gradient of the terrain, providing important data for construction, erosion control, and land management purposes. Understanding this concept is crucial for effective planning in environmental and engineering contexts.