GIS: Downloading GIS Data

LAB 3: Downloading GIS Data

Introduction: The overall goal of this lab was to retrieve data from the internet to portray Census Information for the state of Wisconsin. In order to achieve this goal I had to follow a series of objectives. I had to learn how to download census data, in this case it was the total population from the Census Bureau Website. Then I had to download shapefiles of Wisconsin counties from the same website so I could then represent the data on a Wisconsin map. After this I learned to join the actual data to shapefiles so I could then map it.

Methods:  the first step was to locate and download the actual data from the Census Bureau. In order to do this I had to do an advanced search to find the total population data. After I narrowed down my search to find the population data I checked the box next to the data I wanted to download and saved the zip file in a folder, where I then extracted it. After I had the population data I had to download the shapefiles that I was going to use to portray the information, in this case Wisconsin counties. Through the same website I downloaded Wisconsin counties as a shapefile into the same folder.

After I had all the data I needed I could then start using ArcMap to map the data. The first step was to add the Wisconsin counties shapefile to the map. After that I had to open the population data in an excel document where I could then save it as an excel workbook. Once it was saved as an excel workbook I could then use the table it in ArcMap and then join the data with the Wisconsin counties shapefile attribute table. To join the two tables, I had to find a common attribute between two tables which was the GEO#id attribute. I could then join the tables based on this attribute and thus represent the population data through the Wisconsin counties shapefile.

Because the tables were now joined by a common attribute I had to then create a map to portray the total population of Wisconsin by county. However I first had change the population data column in the attribute table of my counties shapefile to a number type. To do this I added a second column formatted by number type and essentially copied the data from the original population column to the one I recently added. This was necessary in order to be able to symbolize the data under the properties menu. I then opened the properties for the Wisconsin shapefile layer so I could symbolize the population data by a graduated colors map. I selected the value in which represented population and chose an appropriate color scheme and number of classes. Once the information was displayed appropriately through a graduated color symbol map I then added the appropriate tile, legend, and scale bar to the map in order to create a more aesthetically pleasing map.

After establishing a final product representing total population I then created a map similar to this using a different variable. Even though the steps used to produce the second map were the same, the data which was downloaded through the Census Bureau was different. Instead of total population for the state of Wisconsin, the second map portrays the number of households per county symbolized by a similar graduated colors map.

Results:  

       

















Sources:
US Census Bureau