The Generalisation Necessity

On a map, the available space for all the cartographic representations of the objects and elements of a landscape model, is very small and decreases disproportionately from scale to scale.
Therefore a limitation on the essential map elements and objects is necessary with the reduction of an image area from scale to scale.

Characteristics of generalisation are:

• An extreme reduction compared to reality. Example: with a 1:25 000 scale, the image area 625 million times smaller than reality.
• A pure photographic reduction of the original scale leads to an illegible map.
• Already in the 1:25 000 scale, many objects of the landscape cannot be represented any more.
• At smaller scales, a representation of all objects of the landscape is impossible.
• A complex and unclear structured reality must be simplified according to the scale of the map.