The most
succinct definition of a map (referring mainly to a
topographical map), that has stuck with me for years, is this:
"A map is a 2 dimensional representation of a 3 dimensional shape, showing natural and man made feautres, drawn to scale, at a particular point in time." - Australian Cadet Manual
A little analysis of the components of the quote:
- 2 dimensional - a map is DEFINED as 2 dimensional, as anything else is a model
- Representation - a map may not have every detail possible on it. A topographical map will have contours and natural features like rivers and the like, maybe even buildings, power lines, zoning information etc, but will not show every tree, rock or the like. Even photorealistic maps (think Google Earth) miss out information, like readily-available contours. Superimposing maps on to each other in layers can help this to a degree
- 3 dimensional - a map (in this definition) represents the real world or an object within it, so it tries to convey 3 dimensional concepts on a flat (2d) surface. As a result, cavity shapes and muliple level shapes are difficult to represent, however multiple maps (or colour schemes) can still present a close to complete picture. Think blueprint
- Shape - the thing being described. Esoteric shapes may be wind currents, tides, weather maps, but still meet all the other requirements for defining a map
- Natural - maps should try to show ALL natural, theoretically PERMANENT, features. Rivers, mountains etc
- Man made - again, easily identifiable features made by man should be noted on any map. Rainfall map? Note a dam, to indicate a higher level of evaporation...
- Drawn to scale - without being accurate scale, it isn't a map, it's a diagram. Scale allows different areas within a map to be compared directly and equally. Two points can be navigated to, comparisons on their surroundings can be made and information compared. Scale is without doubt the most important feature of a map
- At a point in time - maps by definition are are not dynamic or self-updating. If they were, they would be a feed (yes, that is the term used by the Australian Army). Maps all age from the instant they are completed. As a result, it is inherent that the older the map, the less accurate it is.
ALWAYS USE THE MOST UP-TO-DATE MAPS YOU CAN!
Amazing what you can derive from one short definition!