Quantifying the extent and cost of food deserts in Lawrence, Kansas, USA
In an article by Lucius F. Hallett IV and Dave McDermott, ‘food deserts’ in the small town of Lawrence, Kansas, are examined and calculated with the use of geographic information systems (GIS) and an array of surveys. The term ‘food desert’ was first used in the early 1990’s to refer to areas where there is no access to adequate, nutritional food sources. In order to compose their map, important factors such as the location of grocery stores, distribution of population, cost of access to food, and information regarding shopping preference had to be quantified.
When determining the location of grocery stores, Hallett and McDermott decided that they would only include full-service stores, or stores with a size of, or greater than, 30,000 square feet. The sizes of the stores were measured by using air photos from the National Agricultural Imagery Program (NAIP). In addition to the location of the stores, 4,000 surveys were sent out to the four zip codes within the city of Lawrence. These surveys asked shoppers questions regarding forms of transportation taken to the grocery store and, also, travel time and distance. Due to the fact that travel is required to obtain food, a cost surface analysis of total expenditure is created. Hallett and McDermott measured the total cost of travel, the total cost of food, and then compared the two figures to determine which of the survey participants spent the most amount of their time and money to obtain food and in what area of Lawrence they were located.
The location of the full-service grocery stores can be seen in the map above. There are areas in Lawrence where it appears that the stores are either evenly distributed (Northwest corner), closely grouped (Southeast corner), or almost non-existent (Southwest corner).
Using GIS to assign values to the routes that can be taken to grocery stores and calculating the cost of transportation along those routes, Hallett and McDermott concluded that no resident in Lawrence that owned a car lived in an underserved area. In contrast, residents without cars that live in older neighborhoods were found to be underserved when their food costs were compared to their food cost, travel time, and distance required to travel in order to get food. In short, those who owned cars were not affected by the food desert phenomenon, while those without cars were affected.
After assigning colors to the different levels of poverty in Lawrence, Kansas, it becomes clear that these supermarket chain stores are more likely to be found in the under-served areas of the city. Conversely, the inner city contains almost no supermarkets. This seems to portray a possible food desert, but due to the lack of poverty in the inner city, shoppers in this area are more likely to shop at smaller, high end stores, which are not represented on this map.
The overall cost of food is ultimately considered to be spatial. In areas where the population is primarily under-served, big name, chain grocery stores are likely to be found due to their lower cost of food. Conversely, higher priced stores are likely to be found in more affluent neighborhoods due to the preferences of shoppers. Hallett and McDermott conclude that an inherent value can be placed on food, based on perceptions, ideas and lifestyle. The process of obtaining food is relative to each of the different people walking or driving to the store and even by quantifying the time that is spent, distance that is traveled, and the cost of obtaining food, the lines of what is technically considered a food desert in Lawrence, Kansas, are still blurred and open to interpretation.
Hallett, L., & McDermott, D. (2011). Quantifying the extent and cost of food deserts in Lawrence, Kansas, USA. Applied Geography, 31, 1210-1215.