Distortion on a flat map, also known as map distortion, refers to the inaccuracies or alterations in the representation of the Earth's curved surface when it is projected onto a two-dimensional flat surface. Since the Earth is a three-dimensional sphere, any attempt to represent it on a flat map will inevitably introduce distortions in one or more aspects of the map.
The main types of distortion that can occur on a flat map are:
1. Shape distortion: This occurs when the shapes of geographic features, such as countries or continents, are distorted compared to their actual shapes on the Earth's surface. For example, on some map projections, areas near the poles may appear stretched or distorted.
2. Area distortion: Area distortion happens when the relative sizes of regions or areas on the map are not accurately represented compared to their actual sizes on the Earth. Some map projections may exaggerate the sizes of land masses or make them appear smaller than they are.
3. Distance distortion: Maps can distort distances, making objects or locations appear closer or farther apart than they are in reality. This can affect measurements and calculations involving distances.
4. Direction distortion: Directional distortion involves the misrepresentation of compass directions or angles between points on the map. It can affect the accuracy of navigation and direction-based information.
Different map projections attempt to minimize or balance these distortions, but it's impossible to completely eliminate all forms of distortion when projecting a spherical surface onto a flat plane. Mapmakers choose projections based on the specific purposes of the map and the aspects they want to prioritize, such as preserving shape, area, or distance accuracy. Each map projection comes with its own set of trade-offs in terms of distortion, and the choice depends on the intended use of the map.