U.S POPULATION DATA

           This map illustrates the population in each county. The darker the shade of purple, the more people live in a given county. Contrastingly, the lighter shades of purple indicate areas with a small population. Areas in the Midwest, for the most part, seem to have significantly lower populations than counties along the West Coast and Upper East Coast. Large cities tend to have the largest populations.

           This map shows the percent change in the total population over a decade. The colors gradually change from orange to dark purple. Orange indicates a percent loss, as more people move out of those counties than into them, while dark purple indicates a percent gain as more people move into those counties than out of them. The counties highlighted indicate that places losing people are rural whereas purple counties are cities that people are moving to.

          This map indicates the population density of each county in the year 2000. The colors change from light green to dark blue, from low density to high density. The right half of the country appears to be more dense than the left, which more counties shaded darker green and dark blue. It is interesting to note that the counties become increasingly smaller as you move from the west coast to the east coast. This trend is rooted in history and the westward expansion that took place during the late 1800s and early 1900s.

           This map illustrates the change in population over a decade. It hints at migratory trends: the Midwest seems to have lost significant amounts of its population, as indicated by the bright pink. Meanwhile, the dark green indicates that Southern California, Arizona, and Florida have seen a huge increase in population. It suggests that people moved out of the rural areas and into the more urban places. In addition, this may be due to demographics: as the baby boomers age, more retire and move to states such as Florida.

           Though each map has a different focus, they all lead to similar conclusions. While accurate conclusions cannot be made without more information, the maps demonstrate that the U.S population is heavily concentrated around the coasts while the Midwest is losing portions of its population. The ability to visualize all this data helps convey the information in a much more appealing way, thanks to GIS. GIS maps help relate accurate information without the hassle of long spread sheets. Going through the Excel sheet, with the same information, is very intimidating and GIS helps to make it easier and understandable.

DEM: Digital Elevation Model

The geographic coordinate system used for this DEM is the NAD83 (the North American Datum 1983). The extent information is: from top to bottom 39.8929°N to 39.3838° and from left to right -105.7889°W to -104.9694°. From the Aspect Model, it can be seen that the area largely faces south or southwest. The rightmost part of the map, however, faces west or northwest. The Shaded Relief Model indicates that the elevation on the DEM decreases as it moves to the east. The Slope Model, which reflects the steepness of a given surface of a DEM, shows that the elevation is relatively low, with the far right ranging from 0 to about 944,113 feet. In some places, however, the elevation reaches, and exceeds, 8,497,016.472 feet. 

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.

Lab 4: Proposed Airport Expansion

         My First ArcGIS Experience 

           My ArcGIS experience went relatively smoothly; I was able to follow the instructions and other than a slight panic attack, I felt confident in what I was doing. The step-by-step instructions and the accompanying pictures were simple and easy to follow. In addition, there were one or two sentences before each task that explained what I would be doing. These were really good, however I felt they weren't sufficient. A lot of the times, I didn't fully understand what I was accomplishing exactly and sometimes felt that I was simply clicking buttons. However, when I saw the changes on the map, I was better able to comprehend what was happening. Also, it was really helpful when Jason, my T.A. explained what each step meant in terms of the bigger picture.

            The entire experience was really interesting overall. Though I don’t know where the data came from, it was fascinating what a couple of random pieces of information could create. I liked how the information could be layered in different ways to create maps that each represented something different. Also, creating graphs on ArcGIS is much easier than doing it on Excel.

            GIS has the capacity to perform various tasks to help convey evidence. Information can be taken and converted into multiple visuals to prove a point or show a plan. Because access is readily available, anybody can use it. Furthermore, the step-by-step instructions allow people to quickly learn the skills necessary to operate the system. Many news stations use GIS to present a visual for the information they are conveying, helping further the understanding of viewers. Companies in general can use GIS to present visuals about their plans and city planners can use GIS to figure out what the city needs and the best place to put it.

            Unfortunately, in my case I didn't completely understand what I was doing or what the function of each specific step was. If someone does not understand what she is doing, then it is really easy to misrepresent or misinterpret information. GIS requires a basic understanding of what each step requires and what it signifies. It may be difficult for some to get a firm grasp on the concepts and so the maps created may not be accurate. In addition, people can misuse GIS to easily skew information to fit their needs, leading to many false notions.

            Overall, I enjoyed using ArcGIS, especially when viewing the end product and learning what it all signifies.