12. Importing CSV file and Geocoding Addresses
Now we’re ready to import our next mapping layer. This one will be the CSV file that we have of several BLM protests that took place during one week in June. We want to layer this data as points. The point layer will be displayed over the polygon map layer to see if the protests tended to take place in neighborhoods that were majority Black, or not. Let’s import the file.
- Select Add.
- Select Add Layer from File.
- Select Choose File, and navigate to where you have the file
1 Week of Protests.csvsaved on your computer.
- Select Import Layer.
At this point a box should appear that says “Add CSV Layer” at the top and has information about location, coordinates and addresses.
This is the ArcGIS’s way of asking you if you want to convert the addresses that are stored in the CSV file into points on the map. This process is called “geocoding.” Geocoding is a spatial process that uses a geographic address locator to match addresses with location coordinates and create a point layer. It turns a text file (CSV) into a vector file (points layer). This process will only work if you have addresses or coordinates stored in your CSV file, and luckily we do! If you open the CSV file in a spreadsheet manager, you’ll see that we have the fields
zip. This is all the geographic address locator will need to be able to locate the address for each protest and create a map layer of points. To geocode the CSV file, the Field Name column (pulled from the CSV file) needs to match with the Location Fields column (which is the geocoder column). Make sure that the following fields match:
- Field Name: Address = Location Fields: Address or Place
- Field Name: City = Location Fields: City
- Field Name: State = Location Fields: State
- Field Name: Zip = Location Fields: Zip If they don’t match, then click on the cell(s) to change it. Most likely, since the mapping software is pretty good at this stuff, they will all be automatically matched, so you won’t have to change anything. Finally, click Add Layer.
Note on Geocoding Limits
Note: ArcGIS will only geocode up to 100 entries. If you have more than 100, you can use the Census Geocoder which allows you to geocode up to 1000 entries.
Challenges for lesson 12
Terms Used in Lesson
Terms Used in Lesson
Can you define the terms below? Hover over each of them to read a preview of the definitions.
is a spatial process that uses a geographic address locator to match addresses with location coordinates and create a point layer. It turns a text file (e.g. CSV) into a vector file (e.g. points layer).