Google Fusion Tables makes it very easy to create your own maps. The Google Fusion Tables tour is a great place to start to learn how to get started and to see examples from sites that use Fusion Tables. Google has a list of tutorials available for Fusion Tables.
While Google Fusion Tables will map out tabular data that has at least one column identified as a location field. Google can automatically identify some columns as location fields and this will be obvious when browsing the table as the values in those columns are highlighted yellow. To manually identify a field as a location field, you need to view the table, then select Edit –> modify columns. In the popup, then highlight the field and set its Type as location. Once the field has been set as a location column, the records will be highlighted yellow. To then map out the values, go to Visualize –> Map. All tabular data is geocoded as point locations, even if the values in the location are for an area such as a country or state. You can visualize as a choropleth map area data by choosing the Visualize –> Intensity Map option but there are no controls over the gradient values or color choices.
To really take advantage of the mapping options under Google Fusion, you will need to join (or fusion) tabular data with geographic data. The only geographic file format that Google Fusion Tables will import is KML. If you are working with shapefile data, there are a few options out there but the easiest method is to use the Shapefile to Fusion converter called Shpescape. Developed by Josh Livni (now with Google), Shpescape can convert a zipped file containing .prj, .shp, .shx and .dbf files directly to a Fusion Table within your docs.google.com. You will need to supply Shpescape with authorization to access your Fusion Tables but it’s the only straightforward way to directly import shapefiles. Other methods require the export option of an existing GIS software package such as using the export to KMZ tool within ArcGIS or exporting a shape file out as a KML file from QGIS. The KML file then needs to be imported into Google Fusion Table.
Once you have the geographic boundary file imported, joining it with other tables is pretty straightforward. Open the table containg the imported geographic data and select the Merge option. In the Merge with box, type the name of the attribute data that you want to join. Select the matching fields for both the geographic and attribute tables to merge. Once the attribute data is merged to the geographic data, you can now take advantage of the visualization, map styles, and info window configuration options.
Poynter has step by step instructions on “How to make a heat map with Google Fusion Tables“. The tutorial is adapted from a workshop that Google Developer Programs Engineer Kathryn Hurley offered at Hacks/Hackers NYC. John Keefe also describes his work effort to map out U.S. Census data for WNYC.
Related Google Fusion Tables Resources:
- How To Import Data and Make Maps with Google Fusion Tables
- Interactive Map of Heavy Metal Bands By Country Per Capita
- Heat Maps in GIS