Lab 7: Census 2000/2010

These population density maps were created using geographic data from the 2000 census. This first map represents the percentage of Asian-American citizens per county in the United States of America. Areas with a large percentage of Asians include northern and southern California as well as Washington. It is interesting to note that the Northeastern region and the West coast appear to be areas of dense Asian-American populations.

This second map depicts the percentage of African Americans dispersed throughout the continental United States as of the 2000 census. This map analyzes the concentration of the black population across the lower 48 states by county. Most of the black population is concentrated in the South, especially in Louisiana, Mississippi, Georgia, and South Carolina. In addition, in other regions of America, the black population is concentrated around urban centers, such as Detroit, Michigan and Los Angeles, California. Consequently, fewer percentages of African Americans can be found in states in the midwest.  

The final map shows the percentage of other races alone according to the 2000 census. It is the population density map of the United States representing races other than Asian, Caucasian, African-American and Hispanic. In this map, we see that by far the largest percentage of "other" races live in the American Southwest. We can see that the percentages are much higher on the western areas of the United States, especially in southern states like Texas. This map is an interesting because a variety of “minority” races were used to create this distribution.

Conclusion

Once I was finished mapping the census data of these races, I was able to analyze the data and reach several conclusions. First, each race tends to cluster into certain regions of the country. For example, in the maps it showed that Asians settle along the Pacific coast, blacks reside in the Deep South, and the "other" races live throughout the Southwest. However, each race appears to settle within the urban centers of their chosen regions. A second observation I made was that each race is represented in almost every county. With few exceptions, every county across the U.S. has an Asian, black, and "other" race presence. Although these populations may be small in most counties, they still hold significance to the culture of American society. These three maps illustrate that America is a melting pot but also that different ethnicities incline to live with their own respected race.

Overall Impression of GIS

After taking this course my outlook on GIS and maps has changed significantly. Over the course of this quarter, I have come to realize the enormous potential of GIS. At first, I thought GIS involved taking measurements of altitude and recording them in a notebook, but this course showed me the vast capabilities of GIS and its increasing popularity as it is integrated into our everyday lives. GIS technology provides a unique geographical tool that assists the general public in their understanding of the world. GIS software can transform data into visual and dynamic models that can help to solve some of the world's greatest problems. GIS can manipulate census data to help predict political outcomes. GIS can manipulate forest fire data to aid in fire investigations and prevent future wildfires. From mapping out simple mashups on Google Maps to generating 3D renderings of a geographic space, my knowledge of GIS has changed the way I see maps.

Lab 6: DEMs in ArcGIS

Shaded Relief Model

Aspect Map

Slope Map

3-D Model

Extent Data:

Top: 34.1966666658 

Bottom: 33.8680555546

Left: -118.634166666

Right: -118.159722222


For this week's assignment I chose to create a DEM on the Los Angeles basin area. I included the Santa Monica Mountains as well as Santa Monica to Pasadena. The DEM was taken from the USGS Seamless Data server using the 1983 North American GCS datum. I chose this region for a variety of reasons. For one, it is relevant to me. I live in the Los Angeles area so I found it interesting to learn more about my city. The maps display flat plane regions with little change in elevation. However, it still possesses mountains which make for more interesting aspect maps and 3D models due to abrupt and large elevation variations.  

Lab 5: Map Projections

Map projections are a necessary part of creating maps and very useful in ArcGIS. They are useful because they let someone visualize a three-dimensional globe on a 2-d plane. However, although map projections are useful, there are also pitfalls to transferring a 3-d object onto a 2-d plane. No matter how you project the globe onto a plane, distortions in your map are bound to happen.

A map can be projected in many ways and each is suitable for different situations. Conformal maps such as the WGS 1984 Mercator and Mercator projections illustrated above preserve the angles of points at small distances. Pilots can find these maps useful because the angle at which they turn is very important. However, pilots favor maps, such as the Lambert Conformal conic projection, that are both conformal and equidistant. Equidistant maps, such as the equidistant conic and cylindrical projections, preserve the distance of places to each other. A pilot would find an equidistant conformal map projection useful because it would increase accuracy in the angle they have to turn and the distance they have to travel. In addition, there are also maps that preserve area, such as the sinusoidal and Mollweide projections above.

Projections can also be categorized into the type of surface used to project them. Sinusoidal projections keep the north-south and east-west scales the same. Cylidrical projections tend to stretch distances east to west when meridians are mapped to equally spaced vertical lines. An interesting trait about these was that the length of each longitude line was the same no matter how far from the equator. This did not happen with the Sinusodial projection. Conical projections can help minimize distortion from projecting a 3-dimensional object to a 2-dimensional surface.

Map projections must be made to suit the user's needs. As mentioned earlier, pilots may prefer the Lambert conformal conic projection, while the Mollweide projection provides a neater view for world maps. Overall, the main thing to look at is what part of the globe you need preserved. Whether it is area, distance, angles, or even a mixture of them all. Once you have established your need, you can choose the projection most suitable for you.

Lab 4: Introducing ArcMap

This was the first time I have ever used ArcMap or anything like ArcMap. My first experience with ArcMap was surprisingly easy, but only after my first attempt. I had trouble adjusting myself to the different controls and buttons of the program. It was frustrating trying to adjust the resolution of the images and it took me a while to figure out what the two "pan" buttons did. Not only that, but adjusting the scales and legends took a lot of time and patience as well. It actually took me quite some time to finish this lab. However, after a while I was able to go through the process without having to constantly look at the instructions and the process went smoother. The work was a bit tedious but in the end I was able to create a map that gives details and spatial information on a proposed airport expansion.

Like all things, the ArcMap program is not perfect. For one, GIS is a complex subject and the program used for this assignment could be considered just as complex to some. The software seems very sensitive and just clicking on the wrong button may lead to some unintended results. It can lead to a map being deleted or it could undo a time-consuming step. In addition, oftentimes, settings are deep within the program, and unless you are extremely familiar with ArcMap, they can be very hard to find. It takes a while to become familiarized with the complicated features on ArcMap. Users may become frustrated and overwhelmed with all the buttons and controls. There is definitely a lot of patience needed to use a program as complex as this.

Nevertheless, ArcMap is a very helpful program that has many benefits. The data provided by the maps on ArcMap give many layers of information that could be used to make the most informed decisions. ArcGIS has a robust system for creating very accurate road segments at the exact angles you would like. ArcMap also provides people with an organized view of a certain model they are creating. Working with multiple properties becomes fairly easy with ArcMap’s table of contents and the ability to toggle on/off aspects of your map. Additionally, ArcMap allows you to let the different components of your maps interact with each other. You can find areas of overlap, change initial conditions, and change the color to whatever color you want. You could put much detail into these maps. This assignment has barely shown us a bit of ArcMap's potential.

Overall, my experience with ArcMap was a successful one. Although it took me a very long time to finish, I was able to create the map and complete this assignment. Once you are familiar with the program, ArcMap is fairly user-friendly. I am still a bit confused on some aspects of ArcMap, but it is probably because of my lack of knowledge and expertise on geographical data and how it can be represented effectively. Pretty soon I will learn more advanced techniques on map representation. I hope that as we continue to work with ArcMap, I learn the most effective ways to present informative data for the viewer. In conclusion, even though ArcMap may be hard to understand at first, its benefits outweigh its few pitfalls.