Definition of Map Scale
The scale of a map is defined as the ratio of a unit distance measured on the map to the corresponding distance measured on the ground.
At a scale of 1:50,000 one millimetere on the map represents a distance of 50 meters on the ground. At this scale most of the information required by the average map user can be displayed adequately.
Most maps provide information relating to the height of the terrain which they represent, and usually this is achievev by contours, ie, lines joining all points of equal height.
This depends on:
- The vertical interval between contours.
- The nature of the terrain, ie, mountains, moorland.
- Scale of the map
eg, Scale - 1:50,000 Vertical interval in metres, 10 or 20 metres.
It is essential for the user to check vertical interval for any particular map as this may change from one map to the next.
All maps should show some form of graphic scale line which will enable the user to measure the horizontal distance on the map.