The Earth is more or less a sphere, certainly a 3D object (despite some challenges even this), while our printed maps and digital screens are 2D. The intermediate step that transforms the sphere into our 2D maps, whether it be a cartographic atlas or a fancy GIS app, is called map projection.
There are numerous ways to map the ellipsoidal surface of the Earth into a flat surface; however, as these are approximative models, there usually are some shortcomings we need to keep in mind. In some projections, relative angles and polygon (e.g., country) shapes are preserved; in others, the real area or specific Euclidean distances are kept constant. These properties also help you pick the best projection for your use case.
As for the types of projections, there are multiple ways, such as cylindrical, conic, azimuthal, and pseudocylindrical projections. A practical method of transforming from one another is to change the coordinate reference systems (CRS), where Python and the libraries PyProj and GeoPandas came in very handy!
According to Mathematics.com, there are six main categories of projection types:
- Cylindric
- Pseudocylindric
- Azimuthal
- Lenticular
- Miscellaneous
Here, I will not follow such a strict categorization but rather show you nine map projections that I thought looked interesting. Depending on the specific projection, these steps usually result in distortion of shape, area, distance, or direction, so you should choose carefully when going for a real-life project. For that, this collection of projection systems and my code provided below should help. So, without further ado, the maps:
1. Eckert II Projection
Characteristics: The Eckert II projection is an equal-area pseudocylindrical projection. It preserves area accuracy but distorts shapes and distances.
Common Use: Moslty used for novelty maps of the world showing a straight-line equal area…