Activity Overview: The United States Department of Agriculture (USDA) defines food deserts as areas of the country without any fresh fruit, vegetables, or other whole foods. For the past several decades, the middle class migrated to the suburbs from city centers taking their grocery stores with them, leaving only convenience stores. These stores commonly lack an abundance of whole and unprocessed foods, meaning many low-income and urban families lack access to most of the foods that some take for granted.
Time: This page contains a series of activities looking at different kinds of maps. Each activity can be run in succession. Each one takes between 15 minutes and 1 hour.
In preparation for class, load a digital maps tool, such as Google Maps or The National Map from USGS. Use a projector to present this map to the entire class in order to investigate. If digital tools are not available, consider checking out maps or a US atlas from the library. If a projector is not available you can separate students into groups to work with printed or atlas-based maps.
First, use the tools as a class to find the 10 largest urban areas. You can do this by searching the map, using the map index from a glossary or printed map, or by working from students' general knowledge of the location of certain cities.
The ten largest urban areas in the United States by population¹ are:
Then use what the class knows about the cardinal directions and the regions of the United States to classify each of these cities within a larger region. There is some interpretation on the different regions of the United States. If students disagree on the classification, see if they can explain their decisions. Geographic, cultural, and economic factors are all valid qualities of the classification system.
Load the Food Access Research Atlas from the U.S. Department of Agriculture. This map aggregates information about low income populations and populations with low access to supermarkets featuring a wide variety of whole foods.
The green layer represents low income census districts with supermarket resources more than 1 mile (urban) and 10 miles (rural) away. The orange layer represents low income census districts with supermarket resources more than 1/2 mile (urban) and 10 miles (rural) away. The red layer represents low income census districts with supermarket resources more than 1 mile (urban) and 20 miles (rural) away.
Examine the 10 largest urban areas identified in the first activity. You may need to use the map tools to zoom in on these urban areas. Within these urban areas, census districts with lower access will light up as you move through the layers. As a class, identify which regions of the urban areas have better or worse access to whole food resources (supermarkets).
For example, northeast Dallas has excellent access to supermarkets. These districts are not highlighted on any layer of the Food Desert Atlas. Conversely, most of southeast Dallas is more than 1 mile from the nearest supermarket.
In preparing the Food Desert Atlas, the USDA used the Census Bureau's urbanized area definitions, where rural areas are sparsely populated areas with fewer than 2,500 people, and urban areas are areas with more than 2,500 people. A census tract is urban if the geographic centroid of the tract is in an area with more than 2,500 people; all other tracts are rural.²
You and maybe even your class may have a good idea of whether where you live is urban, suburban, or rural based on how you live and travel, but that definition may differ from what is used in this map exploration. If you are unsure if the Census Bureau classifies your census tract as urban or rural, you can use the Census Explorer to find the most recent population estimate for your census tract. Based on the definition, keep in mind that tracts with population greater than 2,500 are urban and all other districts are rural.
As a class, determine if your census tract is urban or rural based on population estimate. Do your students live in more than one census tract? Continue researching to make an accurate picture of your class.
Next, find the city, town, or census tract of your school by using the search function on the Food Desert Atlas or by moving the map using the tools. Is your neighborhood a food desert? Based on the information from the atlas, are you urban and more than 1/2 mile or 1 mile from the nearest supermarket, or rural and more than 10 or 20 miles from the nearest supermarket? Based on your knowledge of the area, can you confirm the data from the atlas? If things don't seem to add up, explain that government data sources are usually a couple of years delayed based on the massive projects required to collect, analyze and publish the data.
Especially if the data layers do not match your or your students' personal experiences, look closer as a group at the publication dates for the different sources evaluated through the course of these activities. Identifying the dates on different sources is the first step to determining whether or not a source might be relevant for a particular research project. Although the purpose of this activity is not to analyze the validity and relevance of different data sources, students should be able to identify a publication date on any resource.
As a class, find the publication date on any paper maps or atlas collections you are using in class. Scroll through the Food Desert Atlas tool to find the date of last update (May 18, 2017). Look at the Census Explorer and other Census Bureau resources to determine if you are looking at population statistics from the 1990 Census, the 2000 Census, the 2013 American Community Survey, or the 2012 Community Business Patterns. If you consult other resources through this investigation, work as a class to determine the publication date on those sources.
Food Access Research Atlas from the U.S. Department of Agriculture