Lab 2: Downloading GIS Data

Goals

The purpose of this lab was to learn how to download data from an online source, specifically the U.S. Census Bureau, create two different maps for the data, and learn how to publish a web map to my ArcGIS Online account. To reach this goal, I utilized many tools I had previously learned and simultaneously learn new ones. These tools and skills included downloading data from the U.S. Census Bureau website, joining data, creating aesthetically pleasing layouts, and uploading the web map.

Methods

I began by obtaining the data from the U.S. Census Bureau's webpage. This allowed me the opportunity to learn how to search for appropriate data on a government website, which will be beneficial in the future. We were given specific instructions with what to look for and download: the table data of 2010 census total population for each county in the state of Wisconsin, the shapefile consisting of the counties, and then another set of table data for a variable of our choice (Figure 1). I chose to map the counties by their percentage of rural land, so I downloaded the “Urban and Rural” data set. I opened Microsoft Excel and saved the CSV file that came from the website to an excel workbook so I would be able to successfully open the data in ArcMap.

Figure 1. U.S. Census Bureau webpage containing the search categories (upper left) and the display of the highlighted areas of the shapefile I downloaded.

I performed a table join with the data from the counties shapefile and the total population data set in order to map the data sets I downloaded (Figure 2 below). Next, I added a new field in the attribute table and used query to copy the data into the newly added field column (Figure 3 below). Then, I mapped the data in the new column in a graduated color display with a Natural Breaks classification containing six classes. I went through the same process in a separate data frame to map the "Urban and Rural data set. Once the mapping processes were complete, I set the data frames up in the layout screen and added pertinent information to each, such as a north arrow, scale bar, legend, title, and source (Figure 7 below).

Figure 2. Join Data screenshot joining counties shapefile and data set table downloaded from the U.S. Census Bureau by their shared fields GEO ID.

Figure 3. Field Calculator copying data from one column to the newly added field column so it's available to map.

Finally, I went through the process of publishing my web map to my ArcGIS Online account. I only wanted to publish the information on the total population by county, so I removed the “Urban and Rural” data frame. To publish, I began by signing into ArcGIS online through ArcMap and sharing my document as a service with the UW-Eau Claire Geography and Anthropology hosted service. Next, I changed the capabilities from "Tiled Mapping" to "Feature Access" and checked the UW-Eau Claire box in the sharing tab. Then, I added some additional information to my web map’s description, such as a summary, description of the map, and tags, then clicked "Analyze" to make sure there wouldn't be any issues when attempting to publish the map as a service. Finally, I clicked "publish" and opened ArcGIS Online in my web browser, added my data as a layer to a map (Figure 4 below), edited the information to match what I had put in ArcMap, and configured the attributes to display the county names and populations (Figure 5 and Figure 6 below). My web map, after finalizing the publish, was then available in My Content of my ArcGIS Online account.

Figure 4. In ArcGIS Online webpage, adding the newly uploaded layer to the web map.

Figure 5. In ArcGIS Online webpage, finding where to configure attributes once added to the map.

Figure 6. In ArcGIS Online webpage, specific configuration of the attributes for the layer.

Results

Figure 7 below showcases the final map results. The total population data frame displays Milwaukee, Waukesha, Dane and other south/central eastern counties contain the highest populations in the state, which makes sense due to the fact some of the largest cities in the state lie within these counties. Counties in central and north central Wisconsin seem to have the lowest populations, likely due to large forests, poor soils for agriculture other than tobacco, and no large cities. The rural percentage map shows central and north central Wisconsin counties having the highest percent, which correlates with their low total population. South eastern and central eastern counties seem to have the lowest percentage of rural land, which also correlates with their higher total populations.

Figure 7. Left: Map displaying total population of Wisconsin counties. Right: Map displaying rural percentage of Wisconsin counties.

Sources

U.S. Census Bureau 2010.