This is your starting file in ArcGIS Pro: It contains state and county boundary data for the entire US. Your maps will focus on a state of your choosing from the list given in the lab document.
For each mapping technique (proportional symbol; dot map), you will create three maps: state-level, county-level, and census-tract level. In addition to using the boundary files provided, you will download and add census tract boundaries, and data from the US Census Bureau's American Community Survey.
Visit US Census Bureau: TIGER/Line Shapefiles [1]. Select the appropriate data using the drop-down menus. Download and paste the zipped folder into your Lab 3 folder, extract all files, and import as a feature class into ArcGIS Pro (see Figures 3.2 and 3.3).
Add your newly-imported census tract data to the Tract_Map. At this stage, you should have three maps with boundaries: state, county, and census tract.
You will be downloading your census data using the US Census Bureau Data Tool [2]
The ACS census data that you download will include demographic data of your choosing for the state, county, and tract level geographies. This demographic data will be in spreadsheet format that you will then join to the TIGER boundary files.
If you use the Advanced Search option in the census data tool, you may find it easier to search for Census data according to specific topics, geography, years, surveys, or codes. For example, assume I am interested in choosing ACS 2015 five year surveys for all census tracts in Ohio for the purpose of examining the number of veterans. Here is what I would search on using the Advanced Search option. The words listed below correspond to the search criteria in the Advanced Search interface. Note that you can narrow your serach for data by clicking on any of the search criteria in any order. Here is the order I used.
For each geographic scale (state; county; tract), open the appropriate Excel file from your downloaded data folder and follow these steps:
1) Delete the top row (you only want one header row; this will become your top row/field names in ArcGIS).
2.) Save-As each Excel file (one per geographic scale) as a *.csv formatted file with a sensible name (so you can easily find it to import).
As you scan through your file, you will see that there are likely a lot of data columns. Choose one column (variable) that interests you. Most of these columns (variables) you will not use for this lesson. Therefore, it is also helpful to delete the columns you don't need for your map, as this will make the table easier (faster) to import and deal with in ArcGIS.
Use the import table(s) function to import your CSV files. Hit F5 (refresh) if your data appears to be missing! It likely just needs to be refreshed.
Refresh your database in the catalog pane to see the tables you have imported.
For each map, we want to join our imported ACS table to the spatial boundary file.
To do this, we want to find the field that matches between the ACS table and the spatial attribute table – we will join them using this field. Figure 3.10 below shows that the STATEFP field in the US_States boundary files matches the Id2 field in our Census data table.
We have one problem: the values in the STATEFP field (boundary file) are stored as text values, but those in Id2 are stored as numbers.
The easiest way to remedy this is to create a numerical field in our spatial boundary data attribute table and use that field to join it to the ACS data table.
Choose “Double” as your Data Type. Don't forget to save!
We will calculate this field by requesting that the new values be equivalent to those in the original text-based field (STATEFP) we wanted to use. In essence, we are creating a duplicate field with the same values, except that this time the values will be stored in numerical form.
Your spatial file should now be ready to be joined to your ACS data!
Add the join, using your newly calculated field and the matching field in your ACS data.
A Few Notes on Joining the State, County, and Tract Level Data.
- For the State table: when formatting the state *.csv data in Excel, add an ID column to the right of GeoID and type the value of the last 2 digits in GeoID (after "US") into each field, ex. 0400000US01 should be 1 or 0400000US10 should be 10.
- For the County table: do the same thing as directed above but type all of the digits following "US."
- For the Census Tract table: instead of creating a field in the Excel file, go into ArcGIS Pro and create a Text field within the census shapefile. Next, calculate the new field to equal this expression: "1400000US" + !GEOID!. Then join the Census Tract table to the census shapefile using that new field.
Before symbolizing your maps, repeat the previous steps (create and calculate new field; join ACS data) for your county-level and census tract-level maps. You will then have three maps ready to symbolize.
Use the Proportional Symbols method to symbolize your data.
Create a new standard-size (8.5" x 11") layout as you did in Lab #1. Insert a map frame and copy and paste it in the layout: this will create three maps at the same scale.
This (Figure 3.20) is just a quick layout example and should not be considered finished! You should follow the guidelines we have learned for creating a visual hierarchy and an excellent layout, etc.
Use the “Save-As” function and save a copy of your map project with a new name (like YourName_DotDensityMaps). This way, you won’t have to add any new data. Creating your second layout will be much easier this way - instead of doing data joining, downloading, etc., you can just focus on the design!
Have fun adjusting your symbolization as appropriate! Try out different colors and symbols. Experiment with the parameters to see what works! The best design will depend on many factors, including the scale of your map, your chosen state, and the data you are mapping.
You are free to edit your data in this lab as needed to clean it up. Delete states (or any type of row) as needed. You may want to make any unneeded boundaries invisible instead, as this will make it easier to bring them back if necessary.
You can change the number of legend items using the symbology pane.
Reference current and previous lesson content for design ideas. Test several layout configurations and lots of symbol designs (sizes; colors; outlines; transparency) – you’ll learn a lot as you go!
Credit for all screenshots is to Cary Anderson, Penn State University; Data Source: US Census Bureau.