1. Measuring Spatial Accessibility to Food Retailers in Leeds Grenville & Lanark

2. Overview
Project assigned as part of dietetic internship student placement
Was an opportunity to pilot the integration of GIS into some of our research/operations
Was very much a descriptive study
Was an opportunity to potentially geographically identify a priority population
Project focus was from a rural perspective

3. Dietetic Internship Project Goals
Primary goal: was to determine the existence of rural food deserts in areas of high deprivation in LGL
Use several network analysis techniques in GIS to assess primary goal
Use measures of deprivation to assess primary goal
Secondary goal: was to validate the precision & accuracy of our food retailer database

4. Dietetic Internship Project Goals
Research Question: “Do residents of LGL with high levels of material, social, and overall deprivation have access within a 16km/20-minute drive time to a Food Retailer?”

5. Defining the Project

6. What are Food Deserts
“Geographic area, particularly lower- income neighborhoods and communities, where access to affordable, quality and nutritious foods is limited”
“Socially deprived areas within cities that have poor access to food retailers”
“Socially distressed neighborhoods with relatively low average household incomes and poor access to healthy food”

7. Identifying Deprivation
Methodology developed by Pampalon & Raymond at INSPQ (Chronic Diseases in Canada, 2000)
Used 2006 Census data at DA level ( persons)
Used education, employment, income, marital status, family structure, & persons living alone as indicators
Material = lack of access to modern goods and conveniences
Social = fragility of social networks
PCA to produce factor scores
Ranked DAs according to factor scores by population weighted quintile

8. Who We Are
A 58/42% rural/urban mix with population or approx. 163,000 persons spread over 22 CSD and 299 DA. (Stats Can, 2006)

9. Defining Urban & Rural
An urban area has a minimum population concentration of 1,000 persons and a population density of at least 400 persons per square kilometer, based on the current census population count. (Stats Can, 2006)

10. Defining Food Retailers
A FR was defined as any major grocery chain or independently owned grocery store as they sell a variety of healthy food products from the four food groups. This would exclude convenience stores, gas stations, etc.
Buffered geography to avoid edge effect.

11. Validating Positional Accuracy

12. Validating Locational Data
The locational accuracy of the data was validated by comparing the positional data obtained from the PCCF (2010) to high resolution aerial ortho-photos (Digital Raster Acquisition Project East)

13. Determining Retailer Coverage

14. Methodology
Euclidean (buffered) method
Network (ORN) method

15. Buffered Coverage
Euclidean Buffer

16. Road Networks
Ontario Road Network

17. Road Networks
Ontario Road Network

18. Buffered vs. Road Networks
The 16 km Euclidean buffered technique tended to overstate the amount of retailer coverage compared to the 20 minute drive time analysis.

19. Determining Food Deserts

20. Mapping Social Deprivation
Overlays of the social deprivation and supermarket ORN layers were analyzed to determine if gaps in supermarket coverage correlated with areas of high deprivation.

21. Mapping Material Deprivation
Overlays of the material deprivation and supermarket ORN layers were analyzed to determine if gaps in supermarket coverage correlated with areas of high deprivation.

22. Identifying Food Deserts
Now that food deserts have been identified we looked at the areas more carefully.

23. Identifying Food Deserts
Now that food deserts have been identified we looked at the areas more carefully.

24. Identifying Food Deserts

25. Identifying Food Deserts

26. Identifying Food Deserts

27. Conclusions
Rural food deserts do exist in LGL in terms of spatial and socioeconomic inequalities
The results suggest that efforts should be directed at strengthening the social networks that would facilitate access rather than the distribution of food retailers
Demonstrated the utility of GIS in giving research added perspective

28. Limitations & Next Steps

29. Study Limitations Assumes all individuals have vehicle access
Cut-offs (e.g.: 20 minutes/16km)
DA is a crude level of rural measurement
Incomplete food retailer database
Many variables affect access
Ecological study/aggregated data

30. Take Home Message Exploratory study
Established baseline for measurement
Process is transferable/scalable
Further refinement necessary
More advanced co-relational statistical methodologies available

31. Thank you for your time John.cunningham@healthunit.org
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