Topography Exercises
- The best way to begin reading and creating topographical maps is to familiarize yourself with the terminology and symbols used to describe each feature. Scale is one of the most important concepts and terms, and will drastically impact how you read a map. Aside from denoting the size of the features on the map, scale also plays a direct role in how the features are described on the map. For example, a map of a mountain range will feature more contour lines and different contour intervals than a map of a hill, even though both the hill and the mountain share similar shapes.
Scale is noted by the following formula: 1:x, where 1 represents 1 inch on the topographical map, and x is the number of inches of the actual object represented on the map. A scale of 1:30,000, for example, is equivalent to 1 inch of topographical map representing 30,000 inches, or 2,500 feet. At this scale, you could represent the crater on the top of Mount Fuji on slightly more than 1 inch of a topographical map.
Contour lines represent equal elevations, while contour intervals mark the changes in elevation between contour lines, and are generally at a set interval. If you have three contour lines that represent elevations of 50, 100, and 150 feet, your contour interval is 50 feet.
Topographical symbols are used to describe aspects of infrastructure, such as roads, railways, bridges and water-related equipment. It is difficult to read a map without knowing what these symbols represent. You can view a full list of the symbols at The United States Geological Survey website. - Once you have mastered the basic terminology of topography, you can attempt to draw your own topographic maps. Start with a simple shape, such a cone. Although the shape itself is not very challenging, the point of the exercise is to become comfortable with working simultaneously with the concepts of scale, contour lines and contour elevations. Without this ability, you will be unable to map complex shapes. Additionally, mapping more complex shapes is often a process of breaking the complex shape down into smaller, simpler shapes.
A cone would be represented on a topographical map by a series of gradually smaller circles. Choose a sensible contour interval. If your cone is 3 feet tall, you may want to have contour intervals of 6 inches, giving you a total of 6 contour lines. Scale your map appropriately so you can represent the entire cone on the sheet of paper. A scale of 1:6, for example, will easily allow you to draw your cone on a standard legal size of paper.
Keep repeating such simple exercises until, when you sit down to draw, you automatically think in scale and elevation. You will then be ready to start learning how to draw far more complicated shapes.
