Putnins P6 Projection
Mar 26,2026

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Introduction

Putnins P6 Projection is a pseudoconic equal-area projection proposed by Soviet geographer A. Putnins in the mid-20th century. Designed specifically for world maps, it aims to accurately preserve the area relationships between land and ocean. In this projection, the Earth’s graticule is projected onto a conical surface and then unfolded into a plane, resulting in meridians represented by straight lines radiating from a common vertex and parallels as concentric circular arcs centered at that vertex. Distortion is minimized near the standard parallels and increases with distance from them, yet area distortion remains zero throughout.

Projection Basic

Putnins P6 Projection is a pseudoconic equal-area projection proposed by Soviet geographer A. Putnins in the mid-20th century. Designed specifically for world maps, it aims to accurately preserve the area relationships between land and ocean. In this projection, the Earth’s graticule is projected onto a conical surface and then unfolded into a plane, resulting in meridians represented by straight lines radiating from a common vertex and parallels as concentric circular arcs centered at that vertex. Distortion is minimized near the standard parallels and increases with distance from them, yet area distortion remains zero throughout.

Pros

Strict area accuracy: As a pseudoconic equal-area projection, Putnins P6 strictly maintains area proportions between land and ocean globally, with an area ratio of 1. It is well-suited for thematic maps requiring precise area comparisons, such as population density, resource distribution, and climate zoning.
Controlled distortion in mid-latitudes: Compared to projections like Sinusoidal or Eckert VI, its radial meridian structure results in less shape distortion in mid-latitude regions, offering a visual appearance closer to the spherical form of the Earth and improving map readability.
Mathematical stability: Based on concentric circular parallels and radial meridians, its computational model is clear and well-suited for academic cartography and theoretical analysis, facilitating the mathematical implementation of equal-area conditions.

Cons

Significant distortion at high latitudes: Near the poles, the strong convergence of meridians leads to pronounced stretching and compression of landforms, severely distorting the outlines of polar countries such as Russia and Canada, thereby reducing geographic intuitiveness.
Aesthetic limitations: Its asymmetric arc structure and outwardly bulging meridians are often considered visually unbalanced in cartographic circles. Lacking the visual appeal of projections like Equal Earth or Robinson, it has not been widely adopted by mainstream organizations such as the National Geographic Society.
Limited software support: Major GIS platforms such as ArcGIS and QGIS do not include this projection by default. Users must manually define projection parameters or rely on third-party plugins, restricting its application in practical geographic information analysis.

Application Scenario

Due to its strict equal-area property, the Putnins P6 Projection is primarily used in thematic mapmaking that requires accurate representation of global area proportions, holding unique value in academic research and education. It is widely employed in population density maps to truthfully reflect the population carrying capacity and spatial clustering of countries and regions, avoiding misinterpretation caused by projection distortion. In natural resource distribution maps, such as those depicting global patterns of minerals, forests, and water resources, its area fidelity ensures the scientific reliability of resource estimates. In climate zone maps, it accurately represents the land area proportions of different climate zones, providing a reliable spatial reference for climate model validation and ecological research. Although modern digital platforms increasingly favor projections like Equal Earth or Robinson for their visual appeal, Putnins P6 continues to serve as a “gold standard” for high-precision cartography in research papers, geography textbooks, and authoritative publications from international organizations—especially in contexts where data accuracy takes precedence over visual aesthetics.