How the Curved Earth Is Represented on Flat Maps
Maps represent a three-dimensional surface on a flat plane. This transformation requires mathematical projections, each of which introduces specific distortions. Understanding projections is essential in cartography and map design.
Why Projections Exist
The Earth is spherical, while maps are flat. Projections translate latitude and longitude into planar coordinates. No projection preserves all properties simultaneously.
Main Types of Projections
Conformal Projections
Preserve local shapes and angles.
Used for navigation and city maps.
Equal-Area Projections
Preserve area proportions.
Used for statistical and thematic maps.
For example, see this – Gall Peters Projection map: >>>
See Dymaxion Fuller projection map: >>>
Equidistant Projections
Preserve distances from specific points or lines.
Compromise Projections
Balance distortions of shape, area, and distance.
Often used for world maps.
Distortion Types
Every projection distorts at least one of:
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area
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shape
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distance
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direction
Cartographers choose projections based on map purpose.
Projections in Design Workflows
Before exporting to vector design software:
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projection choice is finalized
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spatial relationships are verified
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distortion effects are assessed
This ensures visual coherence.
Summary
Cartographic projections convert geographic coordinates into flat map geometry. Each projection balances distortions differently. Professional cartographic production selects projections based on geographic scope and visual purpose.
Author: Kirill Shrayber, Ph.D. FRGS