Efforts to define local food systems are widespread. One popular way to delineate “local” is circumscribing a circle of a radius around a chosen center point. The “100 mile diet” is one such popular definition. An important step in mapping local food systems is that there must be an identification process in order to recognize the relevant components of the local food system studied. To understand the structure and scope of the current local food system in Philadelphia, 'informal interviews were conducted with various participants in the system including urban farmers, Community Supported Agriculture (CSA) owners, farmers’ market operators', among others. Essentially the study aimed to pinpoint the healthiness of local food practices in Philadelphia.
152 routes were computed representing all routes taken by farmers bringing products to the city’s farmers markets. The number of routes is larger than the number of farms because many farms supply more than one farmers market. Each trip is counted independently because most farmers supply markets operating on different days of the week requiring separate travels. In performing this analysis, there was no suggestion that all this land can or should be cultivated for food. Many other factors determine the use of land for food production within the city and require further study.
Kremer, P., & DeLiberty, T. L. (2011). Local food practices and growing potential: Mapping the case of Philadelphia. Applied Geography, 31(4), 1252-1261.