Week 5

The advantage of having many types of map projections is that it is possible to look at a defined area of space from different perspectives.  Generally each of the four principal types of maps has distortions in distance, direction, space, and area.  From the activity in ArcGIS, I learned about the map creation process and the flaws and potential as part of the process of constructing maps.  These observations are detailed in the following paragraphs.

One of the principal pitfalls of these different map projections is the distance portrayed from one location to another.  In this particular assignment, the task was to measure the distance between Washington DC and Kabul, Afghanistan on six different map projections.  On each map projection, the distance changed, and sometimes is different by a significant margin!  For example, on the Mercator map projection, the distance is 10,112 miles, whereas on the Azimuthal Equidistant map projection it is 8,328 miles between the two cities.  As a result, it can be argued that map projections can misrepresent distances.  This pitfall is something to keep in mind, and does not rule out the advantages and potentials of the use of map projections in GIS. 

That being said, the potential is great for using these map projections; they give us different views of the world and have the opportunity to control variables based on what you want to see in a map.  For example, if you want to have an approximate accurate map based on the accuracy of shapes of the landmasses, you would choose a conformal map, or either the Mercator or Stereographic map projections to represent your data.  Naturally, some maps are better fits for certain sets of data, but this gives the user more choices in how to represent them.

Overall, map projections in GIS have a lot of potential in terms communicating information to the viewer.   Depending on the selection of the map, one could emphasize different characteristics, such as the shape of the sites themselves, the distance between the sites and other relevant features, or the area in which the sites are located, among other traits.  It is now much more flexible for all sorts of data, and makes it open to more users.