What Are Topo Map Illustrations?

Using a topo map effectively will allow you to find all the important landmarks while planning a trip into unfamiliar terrain. And, most importantly, your map will tell you a richly detailed tale about the terrain you’ll be exploring.

What Is A Topo Map?

Topographic maps (also known as contour or topo maps) are maps that show land contours and other features. They are a common type of map used by many people, from military and architects to hunters and hikers. Unlike road maps, they don’t show all the detail of a road, but they do show features like hills, rivers, and mountains. They are also useful for planning and navigating, as well as for making outdoor activities safer and more fun. Topo maps are generally printed on paper, though some digital topo maps are available.

Contour Lines

Contour lines are imaginary lines that join points of equal elevation (elevation refers to height in feet or meters above sea level). They show the shape and the relief of terrain features on a map. You will be able to identify contour lines that are close together and those that are far apart, by observing the amount of space between them. When there is less space, the slope is steeper and when there is more space, it is gentler. The shape of a topo map also helps you to identify the contour lines that represent streams and rivers. When a contour line crosses a stream, it makes a sharp pointed V or U-shape. This feature is called a draw and points toward the peak of the ridge it intersects with. Gullies and spurs, which are caused by the erosion of running water on hillsides, also make a U or V-shaped contour line. The closed end of the gully or spur point toward higher elevations, while the open end of the gully or spur points downhill.

Map Scales

Map scales are a critical factor when you’re using a map, both on paper and in the digital world. They help you accurately translate a distance on the map to a corresponding distance on the ground. The map scale is a ratio of the distance on the map to the distance on the ground, usually expressed as a comparison like 1:50000, or written as a fraction or representative fraction (RF). It is shown graphically by bar scales marked in feet and miles, or meters and kilometers. The RF is the most important of all map scales because it reveals how much the real world is reduced to fit the map. It is the most useful scale when you’re measuring a large area such as a world map or a continent.

Map symbols

Maps are made with a system of symbols to convey the relationship between objects, distances, and features. Without symbols, a map would not be possible to convey all of the information needed. Symbols can be abstract or iconic. Pictorial symbols are often used for maps intended for children and non-literate adults. A map key, or legend, tells you what each symbol means. A small black dot, cdot, means a town or village; an open circle, circ, represents a city of at least 75,000 people. The color of each line on a topo map also indicates what type of terrain it depicts. Blue, for example, means water, lakes, rivers, streams and other natural features. Brown, for example, indicates human-made features such as roads and buildings. These contour lines vary in thickness from map to map. The thicker lines, called index contours, are usually marked with numbers that give the height in feet or meters.