A map is simply a pictorial representation of natural or artificial features on the surface of the earth or of the planets, and is a way of making a two-dimensional, geometrically accurate depiction of a three-dimensional space. Each point on a map corresponds to a geographical position in accordance with a particular scale and projection.
Maps are most commonly used for navigation purposes, and include road maps; nautical and aeronautical charts; cycling maps; railroad network maps and hiking maps. They are also extensively used as a planning tool for housing, utilities, businesses, councils and other local agencies.
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| ... that map-making dates back to the Stone Age? One
of the oldest surviving maps is painted on a wall in the Catalhoyuk settlement in
Turkey and dates from about 6200 BC. |
Map Features
Unlike a simple photograph, maps can be selective in the features they display and so are able to show various quantitative and qualitative facts, such as boundaries, physical features, population density or climate information.
In general, maps usually contain the following information:
- The place names of locations.
- Symbols to indicate landmarks and features (along with a key). Landmarks and features may include roads, rivers, footpaths, buildings and railway lines.
- Contour lines to show the height of the ground above sea level and the steepness of the land.
- A scale bar to enable the user to calculate distances.
- A grid system to make allow easy estimation of distances and to enable the user to accurately pinpoint their location.
Map Orientation
Today, maps are conventionally oriented with North at the top. However, this was not the case for many ancient maps; medieval Arab maps placed South at the top, whilst European maps of the same time were centred on Jerusalem, with East at the top. Modern polar maps do not have North at their top either; the pole lies at the centre of the map instead.
If a person is located at a particular point on a map, then the map can be oriented so that every point on the map lies in the same direction as the corresponding point in reality.
Map Scale
The majority of maps are drawn to a scale; this enables the user to establish the actual sizes of, and distances between, objects. A larger scale shows more detail, thus requiring a larger map to show the same area. For example, maps designed for walkers and other outdoor enthusiasts are often scaled at the ratio 1:25,000, which means that 1 unit of measurement on the map corresponds to 25,000 of that same unit in reality (i.e. 1 cm on the map would be equivalent to 250 m on the ground). In comparison, maps designed for the motorist are often scaled at 1:250,000; in this case, 1 cm on the map would equate to 2.5 km. Read on for more details on the information contained in a number of different map scales ...
However, the majority of commercial navigational maps, such as town plans and road maps, often sacrifice an amount of scale accuracy for increased clarity, for example by exaggerating the width of roads.
