Lab 7

 Mapping Census 2000 with ArcGIS

1. This map shows the number of people that lived in the United States in 2000. Different colors represent the different population of that area. For example, the largest population is represented by purple, located at south California and area around New York. We can also see from this map that the population of the middle area is very small. In general, the darker of the color of the area is, the population of this area is larger.

2. This map shows the amount of population changed in the United States from 1990 to 2000. Different colors represent different amount of population changed. We can see from this map that the change of population at the middle area is slight, and at western and eastern coast, the change is very obvious.

3. This map shows the percent change of total population in the United States during 1990 to 2000. Different colors represent different percent of change. The values are calculated by subtracting the number of people present in the year 1990 from the number of people present in the year 2000, and then divide that by the number of people present in the year 1990, and then multiplying it by 100.

4. This map shows the population density of the United States in 2000. Population density is calculated by dividing the total number of people living in that place by the total land area. Different colors represent different population density. We can see from this map that the population density of some big cities is larger than that in some small counties.

This lab asked us to make four maps about the population issue in the United States during 1990 to 2000. I learned how to join attribute data to the map, perform simple calculations within the context of ArcGIS and work with classification schemes and shadesets in this lab. Moreover, I learned a lot about the population distribution of the United States. My overall impression of GIS is that it needs much knowledge of computer and some of its work is very tricky. However, GIS is very effective and convenient to show information on maps. People can get better know to the world around them through GIS.