About Equal Area Maps
The Equal-Area-Maps.com website has been created as a demonstration of the use of equal area map projections for web (online) map applications. The map pages are intended as samples for the final parts of a series of articles about map projections in general and equal area maps in particular. These articles were published on the GeoWeb Guru website in September:
- Map Projections and Coordinate Systems: Part 1 - an overview of map projections
- Map Projections and Coordinate Systems: Part 2 - an overview of coordinate systems and geoids
- Choosing a Map Projection: Part 1 - argues against the Mercator projection for geostatistical applications
- Choosing a Map Project Part 2: Pseudo-conic, Azimuthal, and Cylindrical Projections - looks at some equal area alternatives
- Choosing a Map Project Part 3: Pseudo-cylindrical Projections - completes the survey of equal area projections
- How to Create an Online Map with a Non-Mercator Projection: Part 1 - a tutorial to using these projections with UMN MapServer
- How to Create an Online Map with a Non-Mercator Projection: Part 2 - completes the tutorial by implementing equal area projections in OpenLayers
This website serves as a practical demonstration for the last two articles.
The series' central subject, is that of choosing the correct map projection for online geostatistical map applications. Virtually all online map applications use the Mercator projection. This was invented for 16th century navigation - and it is a very good projection for marine navigation, but it is a very poor map projection when the relative sizes of different areas are important. For example, the Mercator projection makes Greenland look slightly larger than Africa, when Africa is actually many times larger. Therefore geostatistical, thematic, and distribution map applications must use equal area map projections.
This site implements a number of online, interactive maps suitable for global thematic applications. The maps have some zoom & pan capability, although they are intended to be viewed as global maps or with limited levels of zoom. External KML and GeoRSS data feeds can also be plotted on a number of these maps.
The demonstration maps have since been expanded to include a series of polar maps and polar projections. These demonstrate the use of various different polar projections in web maps. Note: Only one of these projections is actually an equal area projection.
As a demonstration application that displays demonstration maps, the website does have some limitations. It is not intended for commercial applications. Winwaed Software Technology LLC (owners of both Equal-Area-Maps.com and GeoWeb Guru) can be contracted to produce online equal area map applications tailored to your specific commercial application.