Lab 7 - Census Data

     The first map produced in this exercise shows the population distribution for Blacks in the United States. As with the additional two maps that were generated for this lab the data is represented as a percentage of the population by county. As you can see in this map the largest concentrations of Blacks in the United States can be found in the South and Southeast.

     The second map created in this series maps the population distribution of Asians in the United States. The Asian population in the United States appears to be more dispersed than the Black population, but little centers of aggregation do occur on the West Coast. The two areas that appear to have the highest Asian populations are the San Francisco Bay area and Houston, Texas. The West Coast makes a lot of sense considering it is the closest part of the United States to Asia. Houston however may not. Having previously resided in Houston I would guess that this has to do with the large Vietnamese population that rivals Westminster and Garden Grove in Orange County, California.

     The final map generated in this series was compiled using data termed “Other” by the Census Bureau. The distribution of “Others” appears to be centered in the Southwest and Western United States. After looking through the various available tables offered by the Census Bureau, I am under the impression that this dataset represents the Hispanic population within the United States.

     These three maps show interesting patterns in terms of place or residence for the different culture groups and races. I would be curious to compare the Black Population map with maps showing population growth and decline for each county to see if some of these areas are experiencing an exodus of the non Black population. In any case, I think the most likely explanation for why these patterns are what they are can be found in the fact that each group finds itself best represented within the population in areas where they tend to arrive in the United States. 

            

     While the census data represented in these maps are definitely interesting, the aspect of this exercise that I appreciated the most was seeing the versatility of the database management tools ArcGIS comes with. Having had some experience with database management software before I found these tools to be amongst the easiest I have ever used for creating joins and relations. Being able to simply drag over tables in excel or csv format and have them relate so effortlessly really is a breath or fresh air.

            

     My overall impressions of ArcGIS are that it is an incredibly powerful tool with nearly unlimited potential. The ability to create these maps using freely available data distributed through the internet has managed to get me interested in making maps that aren’t specific to a class project or my own research. GIS in general and the ability to perform spatial analysis so easily will definitely be on my mind as I move forward with my academic career and consider future research projects. 

Lab 6 - Digital Elevation Models

         These maps portray an area within central Colorado that I used to live near and hike. This area had a large amount of variable terrain and this can be seen clearly in all of the maps, perhaps most dramatically though in the three dimensional one that was created using ArcScene. The GCS North American 1983 geographic coordinate system was used to create these maps. The geographic extent displayed is as follows:

North = 38.387 degrees

South = 38.164 degrees

East = -106.187 degrees

West = -106.601 degrees

Lab 5 - Projections

            Being a three-dimensional object, the earth cannot be readily represented on a two-dimensional surface like a map. In order to accomplish this task cartographers have developed projections using complex mathematical formulas. If you look at the maps above, you will note that each projection displays a different distance for the route between Washington DC and Kabul. This is because of differences in the mathematical calculations and the specific intentions of the cartographer. When working with a map projection you have to decide which real world features are most important. Is distance between two designated points most important or do you want that feature more generalized across the entire map? Cartographers have to take this and similar questions into account when they make their maps.

            Conformal projections, like the Mercator and Hotine projections above, attempt to preserve shape locally. These maps are popular but have limited use in doing good spatial analysis. The Mercator projection for example expands area as one moves away from the equator. The Hotine projection also displays similar area distortions.

            Equidistant projections, like the World Azimuthal Equidistant and World Equidistant Conic projections, have distance calibrated from the center of the map. From this calibrated center accurate distance is preserved. In the maps above however, neither Washington DC nor Kabul are at the center so accurate distance remains distorted.

            Equal area projections, like the Hammer Aitoff and Sinusoidal projections, aim to maintain consistent area. Compared to the Mercator or Hotine projection these maps represent the amount of area that each continent takes up on the globe more accurately. In terms of accuracy for distance these kinds of maps are also skewed.

Lab 4

           ArcGIS is an incredibly powerful software suite. It has become an indispensable tool for geographers and policy makers, but has the potential to be used in a number of fields. This particular tutorial would have been useful for an urban planning commission deciding on whether or not to grant a permit to expand the airport. By using ArcGIS to create maps displaying the geographic areas that would be most affected by an expansion within the noise contour, questions about whether or not an expansion would be advisable can be answered.

            As demonstrated in this tutorial, ArcGIS allows for users to display and represent geospatial data from multiple layers and through relations. In one of the exercises it was necessary to join data from two tables where one outlined the census tract data and the other had population density data. I liked how easy it was to perform a join in ArcGIS, as this can be a really frustrating thing to do correctly in some relational database management software packages. Being able to do this within the program itself rather than requiring the user to manage their data through an outside database is definitely a plus for user friendliness. I also found the way it allows the user to customize their maps and enhance presentation to be very intuitive. In this exercise we used pre-designated styles, but for someone working on a personal project they have hundreds of options. Multiple maps can be created, arranged, formatted, and presented in ways that fit all kinds of different contexts without needing to utilize an outside graphic design suite.

            Despite the user friendliness of database manipulation and built in abilities to enhance presentation, ArcGIS has a steep learning curve. In this tutorial I found myself running into problems every twenty minutes or so. The first problem I ran into dealt with maintaining scale between the data and layout views. I eventually realized I could change it in the toolbar at the top and pan, but initially it just wasn’t working for me. I also closed the table of contents at one point and it took me ten minutes to figure out how to retrieve it. The most frustrating experience however dealt with the exercise in which we were asked to expand the street route going through the airport. I hit something that deleted the arterials_new layer from the table of contents and couldn’t figure out how to bring it up again. After taking a break however I remembered that it had been saved as a data source within the geodatabase.

            For the general public, the usefulness of ArcGIS compared to neogeography tools depends on the questions being asked. ArcGIS isn’t very useful for people who are simply trying to show their friends their favorite surf breaks, taco shops, or other specific geographic locales like these. Simply put, the amount of work that would go into creating a map like this would be excessive. If one were however trying to show the effect of a broader phenomenon upon a general area or population, using ArcGIS would be ideal.