The USDA has a web GIS tool called the Food Desert Locator, and it seems pretty useless to me.
- Zoom in and zoom out.
- Toggle the background between topography and satellite.
- Make the highlighted tracks more or less transparent.
- Search for a given address.
That’s it! I find several faults with this site:
- It’s not very powerful: there’s really not much you can do with it. It’s really only interactive to the extent that you can zoom in. Otherwise it might as well be static.
- The interface doesn’t deal well with the fact that rural census tracts are much larger than urban ones. It makes vast rural regions — half of Arizona and New Mexico, for instance — appear as food desserts, whereas urban regions like LA barely register on the map when it’s zoomed out. This magnifies rural food deserts at the expense of urban and suburban food deserts — a big problem given that most Americans live in metro regions.
- There’s no indication of how it’s determined which tracts are food deserts and which aren’t.
- When you click on a census tract that’s considered a food desert, an info window pops up, but it’s poorly formatted. There’s too much information, some of it’s wonky (“Tract FIPS code”, “Percentage of total population that is low-income and has low access”, etc.), and you have to scroll to read half of it. The fact that they’re doing web GIS seems to suggest that they’re targeting a lay audience, but the information that’s presented is not presented in a way that’s easily understandable for a lay audience.
Overall this map is neither robust nor simple and elegant. It seems to serve no good purpose.