Food desert Map of Brown County, WI

The United States Department of Agriculture (USDA) defines a food desert when a census tract meets the following two criteria (Michele, et al., 2011) : 1. Low income: Any census tract with poverty greater than 20% is considered a low income community. Also, a low income community cannot afford even public transportation or a car-pool. 2. Low access: Census tract with more than 33% of people living more than 1 mile of walking distance in the urban areas and 10 miles of driving distance in rural areas from a large grocery store.

Therefore, census tracts and only grocery stores are considered for the analysis. Moreover, the USDA Food desert does not consider any other food source except a large grocery store. Stores met the definition of a supermarket or large grocery store if they reported at least $2 million in annual sales and contained all the major food departments in a traditional supermarket, including fresh meat and poultry, dairy, dry and packaged foods, and frozen foods. (Alana, 2022).

Travel time is one of the key parameters that is analyzed for food access. As part of the analysis, initially, the grocery stores are separated from the Economic Benefit Transfer (EBT) or Wisconsin QUEST card accepting list. Following that, network analysis is performed using the road network of Brown county. And walk polygons (service area) of 0.25, 0.5, 1, and 2 miles are created from the grocery stores. Then the map is converted into a raster. The raster is reclassed as per the distance from the grocery stores. For instance, a 0.25 mile is scored as 4 points, and anything beyond 2 miles is not considered walkable and therefore given a score of 0. According to  Nike's article  titled "Here's What a Good Walking Pace Looks Like for a Mile," the average walking time of a mile is 15-22 minutes (which is based on a survey spanning 5 decades). Therefore, the walking time for a round trip to a grocery store would be between 30-44 minutes. The grocery store distribution is more concentrated in the city of Green Bay. And the eastern and southern parts of Brown County are deprived of grocery stores.

Median Income is another critical parameter which directly purchasing power of the consumer. A low income corresponds to adoption of fast food and frozen diet. On a long term cosumption of stale diet, it creates unhealthy communities. Moreover, median measurement is statisically robust than average measurement.

For instance, the median household income in Wisconsin is around $63,293, as per the  census bureau  in 2020 US dollars. The interpretation would be at least 50% of Wisconsin's households earn more than $63,293. Therefore, the median income is considered for the analysis. The census tract polygons are symbolized as per the classification (refer to the legend in the snapshot). Henceforth, a divergent color scheme is applied to the map. And the map is converted into a raster using a geoprocessing tool feature to raster. The output raster is reclassed with a score ranging from 0 to 4. Moreover, the red tract is 0, and the yellow tract is 4. And these values do not have any units.

Public transportation and the personal commute are yet other parameters that are analyzed. Moreover, travel is dependent on transportation, and intuitively it corresponds to vehicle ownership in the US. Henceforth, the no-vehicle ownership percentages reflect the low access. For instance, consider a household that is greater than a mile distance from a large grocery store with no vehicle and could not carpool due to huge poverty. It makes it impossible for the household to travel frequently and acquire fresh food. Therefore, household opts for canned and frozen food, which have a lesser nutritional value. The lack of vehicle ownership mostly exists in the city of Green Bay. Interestingly, census tracts with no grocery stores are well equipped with vehicles. However, even with 98-100% household vehicle ownership, the travel times are higher, making them low-access communities. The areas with the highest vehicle ownership are reclassed with a score of, and the least vehicle ownership is scored using reclass raster geoprocessing operation.

The poverty rate is another crucial demographic that would assess the low-access and low-income communities. Moreover, median income and poverty rate have a strong correlation. Nevertheless, a poverty rate greater than 20% is considered a low-income community as per the USDA definition of a food desert. Therefore, the poverty rate is analyzed. The census tracts with a population between 2,500 - 50,000 are considered an urban census tract, and any tract with a population less than 2,500 is a rural census tract. Therefore, the urban census tract record a higher poverty rate and are mostly located in the central part of Brown county. Furthermore, the census tracts with symbology are reclassed, and the highest poverty is classed at zero and the lowest at 4.

Geoprocessing operation is utilized to provide an outlook of food access in Brown county, complying with the USDA food desert definition. The greener areas have better food access, and the orange to red areas have poorer access to grocery stores. Cell statistics -> sum operation results in the following raster (image). However, there are certain drawbacks with respect to the definition of USDA. For instance, USDA proposes a buffer distance rather than a network distance - walking or driving. Also, USDA does not consider the aforementioned food sources like - Cultural grocery stores or EBT accepting stores that would not have an annual income of $2 million, food pantries, meal sites, and community gardens as authentic food sources.

As part of the food access mapping project, various food sources have been identified. Each food source is geocoded and planted onto the map. The food sources considered are: EBT accepting stores ( from United States Department of Agriculture - USDA list ), Grocery Stores, Food pantries, Cultural grocery stores, Farmers' Markets, Community gardens, and Summer Meal Sites. For food desert identification, only large grocery stores are considered.