Which feature is essential in a topographical map?

A topographical map is primarily designed to represent the three-dimensional landscape of the Earth in a two-dimensional format, capturing both the elevations and depressions of the land. This is accomplished through the use of contour lines, which connect points of equal elevation. By illustrating the variations in terrain, a topographical map helps individuals understand how the land rises and falls, which is crucial for activities such as hiking, planning construction, or studying geographical features.

The other options, while important in their own contexts, do not define the primary purpose of a topographical map. Political boundaries may be depicted on some maps, but they are not essential to the understanding of the terrain itself. Similarly, climate zones and population centers can provide valuable information, but they do not convey the fundamental topographical details necessary for navigation and landform analysis. Therefore, the representation of landform elevations and depressions is indeed the essential feature that distinguishes topographical maps.