Sunday, September 28, 2014

Research Using GIS Gives Insight to Extent of Local Food Flows in Philadelphia

Peleg Kremer and Tracey L. DeLiberty compiled statistical and geographic research using some geographic information systems (GIS) methods such as remote sensing to look into the extent of how locally produced the food in Philadelphia is. As they discussed, the industrialized and urbanized food system involving long travel distances from producer to consumer and use of pesticides to preserve food quality that is married with long produce travel distances contributes to negative health effects in both humans and the environment. This travel distance is often referred to as “food miles”, and a general rule can be formed that the more food miles produce must travel, the more negative health effects it will have on the human consumer and environment. 
Kremer and DeLiberty used GIS techniques to compile maps that expressed the distance from producer, in this case it was farms, to consumers. The consumers’ location of consumption was represented by farmers’ markets, the end of the travel route for the produce. According to their data, the average amount of “food miles” on these produce travel routes is sixty-one. Here is a visual representation of these routes compiled by Kremer and DeLiberty’s research that can reveal the extent of food miles in Philadelphia’s local food system:

Kremer and DeLiberty also compiled helpful information using GIS techniques that revealed to some extent the capability of land to harvest food in residential environments. This was done with infrared, remote sensing, GIS techniques that separated types of vegetation, giving way to being able to see potential in residential areas for food production. They highlighted the fact that focusing on the use of residential land would introduce difficulties because of factors such as land quality and residents’ willingness to participate, however, they made an estimation that if even five percent of that land was used, then around 9.9 million pounds of food could be produced at the most local level, which would benefit the consumers and the environment.
Kremer and DeLiberty’s research gives insight to the flow of food in Philadelphia, and can be very helpful to the food-localization movement. To see their full research article, go to:
Works Cited
Kremer, P., & DeLiberty, T. L. (2011). Local food practices and growing potential: Mapping the case of Philadelphia. Applied Geography31(4), 1252-1261.


  1. Interesting map. I think it would be cool to have another map just like the one above, except the new map could show disease rates (obesity, heart disease, etc.) so that a correlation, if any, could be observed between high numbers of food miles and high rates of disease.

  2. Saying that 9.9 million pounds of food could be grown on just five percent of residential land sounds like a lot, but the article should state how many people that can actually feed. This land is already being used for a purpose, so finding an available five percent would probably not be as easy as it sounds.

  3. Although it would be difficult, incorporating more residential food production such as community gardens would be great to see. They would also be helpful in food deserts (which tend to be in urban areas). It would have been interesting if they had included a map that displayed an analysis of urban areas and gave us a visualization of which areas could be used for food production.

  4. As Rebecca stated knowing how many people would benefits 9.9 million pounds of food would be interesting. Nevertheless, I do not think five percent of residential area would have been difficult to find. Although it should have been done before building those residential areas. Anyways, it all comes down to the willingness of the residents to participate.

  5. This is an interesting use of GIS. I would be interested to see if there is any way to label at what distance the negative health effects start to occur. Like Dalton said, it would be also interesting to see a correlation map depicting some health effects that "food miles" cause. Also, it is interesting to see what they call the average amount of food miles traveled is, considering how many points are in such close proximity to the city.