Projections of South America

The purpose of this activity was to use ArcGIS software to produce a smallposter that illustrates the impact of using different map projections have on the size, shape, and orientation of South America.  

Requirements: 

1) Ten overlaid maps of South America, each depicting a different projection . Use hue (color) to make each map distinct.

2) A legend that lists each of the projections, includes information for projection type (conic, azimuthal, etc.), properties (equal area, equidistant, etc.), reference/central meridian, standard parallels, latitude of origin information, and the scale each projection is best used for mapping (world, continents, regions, medium scale, large scale, etc.)

 3) A meridian labeled “60˚ West” placed in its approximate location in the overlaid maps. 

4) Introductory paragraphs that describe what map projections are, issues inherent in mapping a 3-D world on a 2-D surface, explains what conformal, equidistant, and equal area projections are, explain why some projections are better for mapping certain areas or certain scales than other projections, and explain why researchers must consider projections when designing projects that involve geospatial data:

"Map projections differ in many ways, and each projection can greatly a effect the representation of the world

based on its particular method of transferring coordinates and locations from their real world places to a two dimensional piece of paper. Unfortunately, because the earth is a spherical  shape, it cannot be perfectly represented on a piece of paper without distorting some aspect. This means that cartographers must choose a map projection that best suits the data they are trying to communicate. In general, there are three types of projections each with several variations within its category. Conformal projections preserve shapes and angles because any two lines on the map follow the same angle as the corresponding lines on the earth. In contrast, on an equal-area projected map, preserve relationships among areas in real world places and their presentation on the map. Lastly, in an equidistant map, great circle distances are preserved which dissect the earth into two different parts. However, it is important to note that each map projection has its weaknesses, and can only be accurate to a certain extent. Some maps are better for mapping smaller areas, but distort larger areas. Other maps have greater distortion the further west and east you go. For example, a Mercator map is able to show true direction, and is good for navigation . However, the scale on a Mercator map gets larger

the further away from the equator you go. This means that land masses are greatly distorted near the top and bottom of the map, and is not a good world representation. As one can see, this is why cartographers must be selective when choosing a projection type."

Discussion: This map posed many challenges in order get the projections to overlap correctly.  However, once this was achieved, it was relatively easy to assign each projection a color and then create a description for each in the key.  Data was obtained by using ArcGIS to create different projections of South America.  The balance of this map tends to be heavier near the bottom, but is because it is the only location that it would fit do to the requirements of the legend in the project.  With accordance to visual hierarchy, the data of the map stands out most prominently with the title and legend behind it.  The map is also has a reasonable level of clarity and legibility, granted some quality was lost during the conversion to JPEG file.