Steven can plan

Geocoding in Quantum GIS

February 10, 2009 at 12:18 am by Steven Vance
Filed under Software, Tools

Quantum GIS (commonly known as QGIS) is an open-source Geographic Information Systems application that has been gaining ground since 2004. It runs on all operating systems (it began as a Linux project) and you can download it for free.

I used it a couple times because ESRI doesn’t make the popular ArcGIS software for Mac. That’s unfortunate, but like I said here, software, technology and mapping issues can be easily overcome – we can use QGIS to create maps. QGIS, though, is missing one major feature for basic map building: geocoding.

Here’s a step-by-step tutorial on how to bring in addresses onto our QGIS-based map:

To get “batch geocoding” in QGIS:

Go to Plugins>Manage Plugins
Check the checkbox next to “Add Delimited Text Layer
Click Okay to add the plugin to your QGIS

Now you’re ready to do your batch geocoding which you’ll import into QGIS.

In a spreadsheet, create the following columns in a header row (at a minimum): address, city, state. Other fields you can use: description, name, url, zip, image url
Input your data into the appropriate columns
Save the Excel document as a Tab Delimited Text file.
Open the newly created Tab Delimited Text file in a text-only editor (like Notepad for Windows, TextEdit for Mac, or vi for Linux). Select all the text (including the headers) and copy to clipboard
Go to www.batchgeocode.com
In the first text field, paste your text
Click the Validate Source button
In Step 4 on the website, map the columns from your text to their appropriate fields in all the drop down boxes
When you’re done selecting the options, click Run Geocoder.
Copy your now geocoded data back into your text-only editor and save as a new file

Now you’re ready to import this geocoded data into QGIS.

In your QGIS document, select Plugins>Delimited text>Add delimited text layer
In the dialog box, click Browse and find your newly created file
Create a layer name
Since your text file is tab-delimited, make “\t” your delimiter for this import
Click the Parse button to validate your input (Parse will also attempt to find your columns that hold the latitude and longitude)
Ensure the X and Y fields have selected the appropriate columns in your text.
Press OK!

Now you’ll see in your layer list the new layer with the data you batch geocoded. If you want to change the style, right click the layer and click Properties.