Map Keys and Map Scale
The Key To Understanding Maps
Maps can be drawn to represent a variety of information. This information might include things such as roads, tourist attractions and campgrounds, or they might represent the latest weather patterns. The objects on a map are represented using symbols. A symbol is a picture on the map that represents something in the real world. Understanding these symbols requires the use of a key. Maps use a key, or legend, to explain the meaning of each of the symbols used in the map. These keys usually show a small picture of each of the symbols used on the map, along with a written description of the meaning of each of these symbols.
Drawn To Scale
Remember that a map is a visual representation of a much larger area of land. In order to be useful, a map must by necessity be small enough to be handled by an individual. Imagine drawing a map of the Earth that was full-size. Of course this is ridiculous. A full-size map of the Earth would not only be too large to be useful, but it would also be impractical to make. Maps are scaled down so that they fit on the available paper or screen. When scaling down a map, every part of the map is scaled by the same amount. This insures that every object on the map is the same proportion as everything else on the map. If a city is twice as large as a neighboring town, an accurate scaled map will show the same relationship on paper. The drawn city will be twice as large as the drawn town.
Because the Earth is round and maps are flat, it is impossible to create a map with a perfect scale. Some parts of the map will be too large, while others will be too small. The larger a territory represented by a map, the greater that the distortions in scale will be.
It is important that we recognize how to read, understand, and utilize scale as we examine the various maps that we encounter. There are three common methods used by map makers to depict scale. These methods are referred to as the graphic method, the verbal method, and the fractional method.