Map Keys and Scales
Understanding these symbols requires a key. Maps use a key, or legend, to explain the meaning of each of the symbols on the map. These keys show a small picture of each symbol with a written description of its meaning.
Maps show teeny, tiny versions of places in real life. Maps of the United States are usually quite small, even though the US is actually thousands of miles long! So how can you tell how far away things really are just by looking at a map?
Maps use scales to show the reader the relationship between the size of the map and the size of the place in real life. When scaling down a map, every part of the map scales by the same amount. This ensures that every object on the map is the same proportion as everything else on the map.
Notably, there are some shortcomings of scales, especially when hiking. If we’re walking across a flat plain, they’re more or less perfect. But say you’re going through a forest with lots of bends and hills. You really can’t estimate how long your path will be with just a scale, then. In that case, other features, like contour lines, are necessary for navigation.
Types of Map Scales
There are three main types of map scales: graphic, verbal, and fractional. Each of these methods shows the same kind of information in a different way.
A graphic scale depicts scale using a line, with markers like on a ruler. There are many benefits to using a graphic scale. It is a straightforward, easy way to determine scale. Also, if a map’s size gets bigger or smaller, the graphic scale also changes size, so that it is still accurate.
The verbal method of depicting scale uses words to describe the ratio between the map and the real world. For example, a map might say something like, “one inch equals one hundred and fifty miles.” Calculating scale on a map using the verbal method is easy. First, measure the distance on the map. Then, follow the verbal directions to calculate the actual distance.
The fractional method for scale uses a fraction to describe the ratio between the map and the real world. For example, let’s pretend 1 inch on the map represents 50,000 inches in the real world. The fractional scale on the map will read 1:50,000 or 1/50,000. This means that 1 unit on the map represents 50,000 units in real life.
Large and Small Scale Maps
A map depicting a large area, such as an entire country, is a small scale map. To show the entire country, the map must be scaled down until it is much smaller. A small-scale map shows more territory, but it is less detailed.