Monday, December 6, 2010

Lab 8 Assignment




The first map shows the percentage of black people in various U.S. counties. Clearly, the highest proportion of black people is in the southeast where the darker shades of orange and red are concentrated. The rest of the country is shaded in yellow and light orange, meaning these counties have a lower proportion of black people. This map was created by combining county data with population data from the U.S. census. These two layers were joined, and a color scheme was created to depict the various percentages of black people.

        The second map shows the percentage of Asian people in U.S. counties. The highest proportion of Asian people appears to be on the West Coast and in the northeast, along the coast of New York. These locations are represented by shades of blue on the map. On the other hand, most other areas of the U.S., including Central America, contain mostly yellow shading, meaning there is a lower proportion of Asians. Like the first map, this map was created by combining county data with population data from the U.S. census. The two layers were joined, and a color scheme was used to represent different percentages of Asian populations.

        The third map shows the percentage of all the other ethnic races of people in U.S. counties. The highest proportion of these races appears to be on the western side of the United States, stemming from Texas to California. These regions have shades of dark blue, purple, and hot pink. Contrastingly, there are less of these races located on the eastern side of the United States, and these regions are represented by shades of turquoise. Like the previous two maps, this map was created by joining a county data layer with a population data layer from the U.S. census, and a color scheme was created to represent the different population proportions.

        In conclusion, these census maps depict percentage information for different ethnic groups of U.S. counties. By joining layers on ArcGIS and creating a color gradient, this data can be represented visually. The various percentages of an ethnic group are divided by ArcGIS into different categories, and each category is assigned color. In the case of my graphs, darker colors correspond to greater percentages (a greater proportion of the ethnic race). The maps show that the greatest percentage of black people is in the southeast, the greatest percentage of Asians is far in the west and on the coast of New York, and the greatest proportion of other races is on the Western half of the U.S.

        My overall impression of GIS is very high. GIS provides the ability to create an enormous variety of maps, with different projections, themes, layers, types of data, etc. With ease, one can zoom in and out of a map, add shapes and details to the map, change labels, accentuate features, etc. The possibilities seem to be endless. GIS makes it possible to communicate a wide variety of information easily, it provides the ability for people to access map information from all around the word, and makes it possible to pinpoint the location of many of Earth's features. It is clearly an important and highly useful technology for various different people and disciplines.