The purpose of this lab was to demonstrate the downloading and mapping of data from an online service (in this case, the U.S. Census Bureau). This involved understanding how to download the data, convert it into a usable from for ArcGIS software, and then creating and uploading a map as a web map.
Methods
Objective 1: Downloading census data
An Advanced Search was opened in the US Census Bureau Fact Finder website. "People", "Basic Count/Estimate" and "population total" were chosen for the topics. "County 050" and "Wisconsin" were chosen for geography. The data TOTAL POPULATION from the 2010 SF1 Dataset was selected, downloaded, and zipped to a specified folder. The files were then extracted as CSV files and an extra row was removed in order to make the data usable. The file was then saved as an Excel Workbook file to be uploaded into ArcGIS as tabular data.
Objective 2: Downloading shapefile for WI census data
On the US Census Bureau website, the Wisconsin Counties were highlighted on the map and downloaded as a zipped shapefile. The data was then unzipped.
Objective 3: Joining the data
A blank map was opened in ArcMap and the Layers data frame was renamed Population. The shape file and the TOTAL POPULATION excel worksheet obtained from the US Census Bureau were added to the map. The shapefile attribute table was joined to the population table using the common attribute field "GEO_ID".
Objective 4: Mapping the data
A new field was added in the data table in which the D001 field data (population) was inserted using the field calculator and then named "D001_new" so that it could be mapped quantitatively. The population was then mapped with graduated colors.
Objective 5: Mapping a variable
Another data file was downloaded from the US Census Bureau, this time the data containing information about households in Wisconsin counties. It was unzipped and converted to an excel worksheet file. A new data frame was inserted and the WI county shapefile and household data table were added. The tables were joined by the common attribute "NAME" this time. The percentage of family households data was mapped quantitatively using a graduated colors symbol and normalized by total households per each WI county.
Objective 6: Building the layout
The data frame projection was changed to NAD 1983 Central WI State Plane. Titles, legends, north arrows, and scales were added to each map and positioned to be cartographically pleasing.
Objective 7: Creating the webmap
The 2010 Family Households map and Esri basemap were both eliminated. The remaining map layer was exported as a shapefile and added as a new layer. The old was deleted. This made the join permanent so the a feature service could be created from the ArcMap document and published to ArcGIS online. Once the web map was created, the attributes were configured so that only the County name and Population are visible. Aliases were changed to be more clear and population was transformed to 0 decimal places because people cannot be represented fractionally. The map was then shared to the UWEC Geography and Anthropology organization and is visible to the public (see link below).
Results
Below are the resulting maps created from the data obtained from the U.S. Census Bureau. Left: a map displaying the population density of each county in Wisconsin in 2010 (also found as a webmap in the link below). Trends show a higher concentration of people in the southeast corner of the state, and a low density in the northern half. Right: a map displaying the percentage of households in each county which contain families. There is a lower density of family households in the northern part of the state (a trend seen on both maps), and each county appears to have at least 57% of the households occupied by families.
Web map link: uwec.maps.arcgis.com/home/webmap/viewer.html?webmap=9561a511fec549d7bf601573deeda41e
Sources
U.S. Census Bureau, Esri, ArcGIS online.
