Topography is a field of geoscience and planetary science that focuses on studying the surface shape and features of the Earth, and other planets, moons and asteroids. Topography means the description of shape, so when you talk of the topography of the land, you are referring to landscape features including valleys, hills, mountains, lakes, rivers, or the coastline. Any descriptive information about the lay of the land, is part of the topography of that area. Contour lines are used in topographic maps to show elevation and shape of terrain. They are the most distinguishing feature of a topographic map – and connect points of equal elevation. There are three different types of contour lines:
- Index contour – every fifth line is an index contour. These display the elevation of a line, in order to keep the map simple.
- Contour line – lines drawn on a map connecting equal points of elevation.
- Contour interval – in order for a map to be simple and easily read, these show lines for certain elevations only
Image taken from here
An example of contour lines showing topography taken from here