U.S. Census Maps

Using Geographic Information Systems (GIS) is a helpful way to analyze large amounts of data such as U.S. Census Data. In this Lab we used data from the 2000 U.S. Census. Retrieving the data once collected by the bureau is a simple process of downloading information. Fixing the data so that it is fit for GIS analysis is a little more difficult because it takes a lot of attention to detail to ensure that this info in portrayed in a proper manner. As a beginner with GIS, this exercise was tedious but it was helpful in learning basics.

According to the U.S. Census 2000, the black population is more concentrated on the Eastern side of the states. Even more specifically, the Southern region of the east side is the most populated in comparison the rest of the United States. In this part of the U.S., Black populations range from over 50% to about 80%. This is an extremely high percentage as compared to the rest of the population percentages, most of which are under 12%.

The term "Other Population" is defined by individuals who do not fall under the categories: White, Black or African American, Asian, American Indian or Alaska Native, or Native Hawaiian or Other Pacific Islander. In comparison to the Other Population concentrations in other counties, these individuals are concentrated on the West Coast with the highest concentrations in some Southern California counties and Texas. Most of these said counties in California and Texas have counties with populations ranging between 24% to 43%.

The percentage of Asian population is relatively evenly widespread across the country in comparison to the other percentages of Asians. The highest concentrations are in the Southern California region. The rest of the populations across the United States are low, most of which are less than 5%. This five percent is a small percentage compared to the 20-46% concentrated in the Southern California region. 

Digital Elevation Models (DEMs)

3-D Model

Extent

Top: 34.5591666657748

Bottom: 34.213611110196

Left: -118.469444445439

Right: -117.842500000952

I chose an area in the Southern California region to carry out this Digital Elevation Model. I selected an area near the beginning of mountainous range so that we can see different elevations. I used Spatial Analysis methods to get most of these graphs. These Spatial Analysis features utilize raster inputs to carry out these functions. For all the maps, the geographic coordinate system used is the North American 1983 as said in the properties table of the maps.

Map Projections

Distances between Washington D.C., USA and Kabul, Afghanistan:

• Mercator: 10,112.12 miles
• Stereographic: 9,905.71 miles
• Equidistant Conic: 7,083.97 miles
• Azimuthal Equidistant: 8,348.19 miles
• Eckert IV: 7,862.56 miles
• Cylindrical Equal Area: 10,106.32 miles

Map projections help portray a geographic area in a way that would fit the purpose of the graph. Different map projections can cater to help show true direction, shape, distance, or area. However, the major fault of these map projections is that not all of these features can be depicted simultaneously. Above I have pictured six different type of map projections, all of which cater to a specific need. Although these are six different types of projections, they are just the few of many map projections that are under constant revision. 

Conformal maps help with proper display of angles. This feature means that direction is always preserved on the map. Area, shape, and distance are not preserved in Mercator maps. In fact, these features are distorted to help create a neat, rectangular shaped map which is useful for making it easy for visuals. Most of the distortions are at the poles and the most accurate distances are close to the equator. In Stereographic maps, distances are true from the center point and the scale increases as you move away from the center of the map. This map is useful for solving spherical geophysical problems and for maps of the polar regions.

Equidistant maps show true scale between two points. Equidistant Conical projections are useful for displaying regions in the mid-latitudes as it utilizes two standard parallels. Just like the last two map projections, distortion also increases as we move away from the two standardized parallels. Distances are also true along the standardized regions but change as the distortion increases. For Azimuthal Equidistant maps, both direction and distance are true from the center of the point projection. As long as the lines from two points run through the center point, the distance is true. Therefore, as you can compare the distances, the distance between Washington D.C. and Kabul are distorted because they do not run between the center point.

Equal Area maps distort the distances of the oceans to ensure that the continents are distorted as little as possible. The Eckert IV map is very different because it is neither a circle or rectangular map. The curved sides and variation of distances between lines help with reducing polar distortions. Cylindrical Equal Area maps compress the distances at the poles. The polar regions of the map are therefore distorted in shape and may not always be clear to individuals. However the distances at both the poles at two latitudes that lie north and south of the equator. The positive thing about having multiple standard parallels is that distortion of area are minimized at these lengths.