MAP PROJECTIONS: Conformal, Equidistant, and Equal Area

The significance, perils and potential of map projections

      There are three main forms of map projections-conformal, equidistant, and equal area. Within these three categories there are subtypes of each map, often based on what the map primarily focuses on. A conformal map is generally defined as one that has right angles from where the lines of latitude and longitude intersect. The most common is the Mercator map, as depicted above. An equidistant map is categorized as portraying accurate distances from its center point. For example, the Asia North Equidistant Conic is an equidistant map with a center point of Asia. This means that distances from Asia to elsewhere tend to be highly accurate, while distances from say Europe to Africa tend to be skewed. The third category is an equal areas map which has accurate relative sizes and true direction. Each type of projection represents accurately in some aspects while distorting other aspects.

      It is very important to note what type of map projection is being presented and the features of each time. For example, the Mercator accurately represents distance, but relative size is way off. If someone were trying to compare the size of continents or countries, it would probably be better to use an equal areas map  such as the North Pole Lambert Azimuthal. In addition, if using a map to calculate the distance between places, the center point of an equidistant map should be considered, otherwise distances may be miles off. For instance, on the USA Contiguous Equidistant Conic projection, Washington D.C to Kabul is approximately 7,297.60 miles. However, on the Lisboa Bessel Bonne equal areas projection, the same cities are measured as 6,934.17 miles apart. Both measurements are taken using the Great Elliptic measure.

      Any form of map in general is going to be somewhat inaccurate. This is because we are trying to represent a three dimensional sphere on a two dimensional piece of paper. The highest accuracy is generally found along the secant or tangent lines, or points in some maps. It is also possible to skew information using map projections which then leads to further inaccuracy. If unaware of what form of projection is being used, information gathered may be inaccurate and result in false conclusions. 

      However, despite the perils, the potential of map projections is great. Because certain data is naturally skewed on a given projection, people can choose which one they want in order to prove their point. For instance, if someone is arguing the distance from Washington D.C to Kabul in shorter than the distance from New York to Kabul, they can use an equidistant map projection that may show New York to be further, even if it actually is not actually further. In addition, map projections allow us to depict our world in a way that is easy to read, causing an increase in knowledge for basic geographical information. News channels can easily show a map of the region being discussed which can help viewers understand the relevance of the issue, especially when identifying the place in relation to their current location. Map projections present our world in a way we understand. However it is important to remember that they aren't a hundred percent accurate.