A map is a scale representation of the earth’s surface. Map scales are usually shown as a ratio e.g. 1:50 000. This scale expresses the relationship between a unit of measure on the map compared with the number of units of measure on the earth’s surface. So in the case of the 1:50 000 scale map, one centimetre on the map would equal 50 000 cm (or 500 m) on the ground.
The best scale to use is determined by the intended use of the map (Table 4.1) and is affected by the intended method of travel through a given area. Someone flying over the alps would consider using a 1:1 000 000 map, a person four-wheel driving may use a 1:100 000 map, and a person walking may choose a 1:50 000 or a 1:25 000 map. A larger scale map (e.g. 1:25 000) can show more detail than a smaller scale map (e.g. 1: 1 000 000).