What do contour lines represent on a topo map?

Contour lines on a topographic map are crucial for understanding the elevation and shape of the terrain. They connect points that share the same elevation above sea level, allowing observers to visualize the landscape's three-dimensional aspects on a two-dimensional surface. This representation of elevation helps users identify hills, valleys, slopes, and flat areas, as well as gauge the steepness of the terrain based on the spacing between the lines – closely spaced lines indicate steep slopes, while lines farther apart suggest gentler gradients. This knowledge is essential for various applications, including land use planning, environmental assessment, and outdoor recreation planning.