In this part of the walkthrough, we’ll try to learn a bit more about the customer base that lives within each 8-minute service area polygon we derived. We’ll accomplish this using what Esri calls “Data Enrichment”, in other words, joining and summarizing attributes from extensive demographic databases.
- In the ArcGIS Online map viewer, open your Delivery analysis map from the previous section of the lesson.
- Click Analysis, and choose Enrich Layer under the Tools section.
- Select your service areas polygon layer as the input features.
- In the Variables section, make sure that United States is selected in the dropdown.
Here’s where you will be tempted to go crazy and add all kinds of interesting demographic and consumer information to your shopping cart of variables. Go ahead and add the following:- Total Population (under Population)
- Total Housing Units (under Housing)
- Went to Family Restaurant/Steak House Last 6 Mo (under Behaviors)
- Have a Smartphone (under Behaviors)
- One other variable you think would be useful for our analysis
- Ensure that you have just a handful of selected variables (in other words, make sure you didn’t accidentally click a whole category and get tons of variables added to your cart).
- Provide a name for the output layer and click Run. Wait a few minutes for the enrichment to occur.
When the enrichment finishes, you’ll see a service area polygon layer just like the one you already have. The difference is in the attributes. - Open the attribute table for the Enriched travel time layer when it appears on your map.
Scroll over until you see some of the new attributes, such as Total Population.
Notice that some of the fields are more useful than others in their current state. We have a smartphone figure that isn’t normalized by anything. We could at least divide that by population to get some kind of an index of smartphone ownership, although it wouldn’t be perfect.
- Since this is a hosted layer within ArcGIS Online, we first need to allow editing of the layer before we can make any changes to the table.
- In a separate browser tab, browse to your ArcGIS Online content and inspect the details page for the enriched delivery areas layer.
- Click on the Settings tab and activate the toggle button to Enable Editing.
- Click Save and return to your map. (You may need to refresh the entire map to ensure that the permissions have taken effect.)
- View the attribute table and click the Fields button in the toolbar along the right side of the window.
- Add a new field of Double Numbers, called PctSmartphone.
- After the PctSmartphone field is added to your table, click the Calculate Field option by its heading.
- We want to calsulate the new field by dividing the "Have a Smartphone" number by "Total Population" for each area. Using the SQL option, add a new filter that calculates the field as MP27002a_B/TOTPOP_CY as shown below. You can also use the fields button "(x)" to see a list of the attributes that you can click to add to the SQL expression; using the search box is very useful in finding the desired attributes.
- Examine your new index of smartphone ownership to see which service areas have the highest ownership.
- Calculate another field called RestaurantVisitRate that represents the number of restaruant visits divided by the number of housing units (NOT population). This gives some idea of the rate of restaurant visits in each service area.
- Look over all the attributes and think about questions like the following: Did the service area with the largest area also have the largest population? Is there any relationship between smartphone ownership and restaurant visitation?
- Save your map.