This study aims to identify potential food deserts in Portland, OR by analyzing the proximity of residential areas to grocery store locations using GIS. The analysis utilizes data on grocery stores, residential zoning, transportation networks, and city boundaries. Buffers of 1/2 mile and 1 mile are applied around grocery stores to identify food access zones, with areas beyond these distances labeled as potential food deserts. The results show most of Portland has food access within 1 mile of grocery stores, with some focal food desert areas identified in the east and northwest neighborhoods. Further research is recommended to consider additional factors affecting food accessibility.

1. Casey Epperson
GIS 4043C.601
Dr. Barnali Dixon
Term Project
1) Title Identifying Potential Food Deserts in Portland, OR
2) Introduction
a) Issue Statement
By identifying individuals' proximity to grocery store locations, this study will identify
food deserts and food access areas within residential areas for Portland, OR. Food accessibility
is a public concern as it adversely affects the health of populations without adequate access,
specifically in regards to malnutrition related ailments such as obesity and diabetes. Food
deserts are molded by a multitude of factors such as historically significant events, landuse and
zoning management, residential demographics, and economic features of revenue and fiscal
investments. Although geographic location of grocery stores is one aspect in determining food
accessibility, it is most efficiently used as a broad indicator that enables further investigation
into identifying potential food deserts and implementing ground-truthing techniques. This
study will utilize GIS analysis to identify food accessibility in residential areas of Portland,
OR specifically focusing on concentrations and deprivation of grocery stores’ spatial range of
influence.

2. b) Objectives
The principal objective of this study as aforementioned is to identify food deserts and
accessibility areas from current information of grocery store locations in Portland, OR.
Accordingly, several factors must be considered in order to determine the geographic range of
food deserts. However, several intermediate objectives must be considered in order to reach
this goal. These objectives include:
• Identify the current residential areas within Portland from 2016 zoning data.
• Identify geographic food accessibility through utilizing current grocery store location in
residential areas within and immediately adjacent to the city of Portland from 2015 grocery
store data.
• Cross reference residential areas with public transportation and analyze the correlation
between areas with food access and areas designated within a food desert area as identified
through this study’s analysis.
c) Justification and Explain
There is a lack of consistency for defining and identifying food deserts, and although a
general GIS analysis of grocery store locations cannot directly determine food accessibility, it
can be a step in further identification of food desserts. A lack of access of foods has shown to
be a public health issue as food deserts have higher obesity rates and malnourishment health
issues than areas that have adequate access. As food deserts are a recent topic in academia, a
understanding and analysis of the literature and awareness of the prevalence of food deserts
has driven the necessity of this study. Although these methods are not the most descriptive,

3. this study could allow for individual populations to tailor the definition of food deserts for a
site by site basis to their particular environmental and social needs.
3) Literature Review
a) Food Access and Food Desert Definition
Food deserts are broadly defined as areas without easy access to healthy foods (LeClair &
Aksan, 2014, p. 537). The interest in food deserts rose during the 1990s and is thus a relatively
modern topic in academia. The exact definition of a food desert is widely debated and has a
multitude of indicators focusing on geographic location of grocery stores, socioeconomic
status, racial and ethnic minorities, and means of transportation. There is a lack of consistency
for which indicators are utilized and to what degree they are implemented for determining food
deserts (Gordeon et al., 2011, p. 696). Some definitions employ a measurement based off of
store locations and employment status (Walker et al., 2010, p. 876), while others include
inadequate private and public transportation issues (LeClair & Aksan, 2014, p. 545). These
areas have been described as a public health concern as they have an abundance of nutrient
poor resources.
In response to the acknowledgement of food deserts, the United States Department of
Agriculture (USDA) has enacted the Energy Act of 2008 which enabled federal research into
the topics of grocery store distribution, nutrition, and food accessibility and quality. The effects
of food deserts is a controversial topic as it evolves into a public health issue in regards to the
obesity epidemic and malnourishment health issues. (Walker et al., 2010, p. 877). In response
to the information gathered on food deserts, the USDA’s Thrifty Food Plan (TFP) records
baseline food prices for low socioeconomic populations (Breyer & Voss-Andreae, 2013, p.
131).

4. i) Defining Food Access Areas via Buffer
Geographically determining food accessibility is found through analyzing
the distance from a grocery store or other type of food retailer and a resident’s
household. This can be calculated using either spatially by walking distance or
temporally by walking time from a resident’s household. Although the assessment
can be contradicted as daily travel throughout the day for work can affect distance
and time to travel for a grocery store, and thus affect food accessibility for an
individual; this exception is not addressed in the analysis of this study currently
(Widener & Shannon, 2014, 2). For urban areas, suggested buffers for grocery store
food access ranged from ⅛ to 1 mile. LeClair & Aksan (2014) suggested that
accessibility between major chain grocery stores command a larger influence, about
½ mile buffer, than smaller, independent grocery stores, about ⅛ mile (540).
Gordon et al. (2011) suggests a ¼ mile buffer of grocery stores as this correlates to
a five minute walking distance (698). Breyer and Voss-Andreae’s (2013) case study
of food access in Portland, OR designated that a 1 mile buffer should be used for
the emergence of a food desert. Although there is further distinguishing of food
accessibility through the quality of food where residents residing within the 1 mile
buffer could face food access hindrances and creating a type of food mirage (134).
This concept of food mirages is further discussed in section 3d, The Food Mirage
and Portland, OR, of this paper.
b) Factors of Food Deserts
The lack of consensus among the definition of a food desert is in part due to the sheer
amount of factors that affect the establishment of food deserts. Socioeconomic status is one of

5. the most prevalent issues in regards to food accessibility. A lower socioeconomic
neighborhood is deemed less attractive for grocery store chains as they would rather have an
established clientele that has a greater buying power than populations on a budget or that utilize
government funds in order to afford basic resources (LeClair & Aksan, 2014, p. 537). The
causes of food deserts can be correlated with the gentrification of urban areas, where grocery
stores are more likely to choose higher socioeconomic areas. The arrival of chain grocery stores
has caused independent stores to close as they normally cannot keep up with the variety of
foods nor the bargain prices of said foods as larger chains could (Walker et al., 2010, p. 876 -
877). These urban populations are further considered unattractive for grocery stores to tailor
to as they are perceived in a negative opinion (Walker et al, 2010, p. 877). Socioeconomic
status and urban development both effect the availability of transportation to grocery stores.
Within urban areas, there is generally a lack of private transportation and thus public
transportation must be used.
c) Effects of Food Deserts
The lack of access to high quality nutritional foods due to a lack of grocery stores has
permitted the establishment of gas stations and convenience stores to dominate the urban
landscape. These store often carry energy dense, high calorie foods that lack proper
nourishment, yet this is all that is available. Over consumption of these foods is prevalent in
these types of urban areas in food deserts, and can led to a phenomena called an obesogenic
environment, where residents are mostly overweight or obese then have obesity-related health
issues (Gordeon et al., 2011, p. 699). Some of the health issues include diabetes, hypertension,
and an increase in heart attacks (LeClair & Aksan, 2014, p. 538). Food deserts are also seen to

6. promote other harmful behaviors to health, including the overexposure of tobacco and alcohol
advertisements (Walker et al., 2010, p. 876).
d) The Food Mirage and Portland, OR
LeClair & Aksan (2014) state that although some neighborhood have been identified as
food deserts, this can be due to either a lack of access to information for the residents on the
locations of grocery stores, the lack of or high cost of transportation, or the high prices
associated with food products within the nearby stores (p. 543). The area of Portland has been
identified as having this issue where there is in fact nearby grocery stores, but the food is
unaffordable and has been overpriced compared to the average amount, called a food mirage
(Breyer & Voss-Andreae, 2013, p. 131). Other than ground-truthing, conventional means of
identifying food deserts through GIS means cannot determine the distribution of food mirages.
4) Methodology
a) Data Sources and Layers
The input data layers I utilized for this original analysis of food accessibility are from two
key sources of open access data from the City of Portland and Oregon databases. The data for
distribution of grocery store locations was obtained from the City of Portland’s Bureau of
Planning and Sustainability (BPS) department. The remaining data layers utilized were the city
boundaries, zoning, water bodies, bus lines, and light rail lines; each of these layers were
obtained from Metro’s Regional Land Information System (RLIS) operated by Oregon’s Metro
Regional Government. More information on the data sources and layers applied within this
study’s analysis can be located in Table 1.

7. b) Data Manipulation and GIS Operations
The first operation for this analysis began with clipping the city boundaries (cty_fill) layer
to the City of Portland and then exporting to create a Portland layer. The zoning layer is clipped
to the Portland layer. This zoning layer is then selected by attribute for the domain values
inclusive of residences: the multi-family residential (MFR), mixed-use residential (MUR), and
single family residential (SFR). This selection is exported into a Residential Zones layer. A
buffer is applied to the grocery stores (grocery_stores_PDX) layer with a mile as the selected
distance, then is further clipped to the Portland City layer and then the Residential Zones layer,
and is finally dissolved to create the Food Access Zones (1 mile) layer. This Food Access
Zones procedure is then applied to the residential zones layer with the exception of enabling a
half mile as the distance for the buffer to create the Food Access Zones (½ mile) layer. The
Residential Zones layer is renamed to Food Desert Zones and is overlaid with the Food Access
Zones (1 mile) and the Food Access Zones (½ mile) layers; and then the Portland City, Water
Bodies, Bus Lines, and Light Rail Lines layers are included to create the Potential Food Deserts
in Portland, OR map, as seen in Figure 2. For each buffer, a separate map was created to
visually demonstrate food accessibility in conjunction with identified food desert areas, as seen
in Figure 3 and Figure 4.
i) Identifying Residential Zones
Throughout attempting to identify food access, the issue of residents and the
definition of food desert became more apparent. An area without any housing cannot
and should not be labeled as a food desert since no established residents would be
affected. At the point, this study choose to include a zoning layer, from which areas
with residents were utilized to indenting potential food deserts. The zoning layer

8. selected zones where the feature was indicated to have residences: the multi-family
residential, mixed-use residential, and single family residential. Although the mixed-
use residential contained both residential and commercial aspects, this selection was
necessary to include all residents vulnerable to inaccessibility.
ii) Buffer Determination
Food accessibility when considering food deserts is geographically determined by
walking distance from a resident’s housing location, although daily travel throughout
the day can affect accessibility (Widener & Shannon, 2014, 2); this is not accounted
for in this study. This study determined that it was beneficial to utilize buffers of 1 and
½ mile, similar to the buffer parameters of U. S. Department of Agriculture (USDA),
as the city of Portland is geographically similar to the fringe between urban city and
suburban housing. A further discussion on buffer distance can be found at section 3bi,
Defining Food Access Areas via Buffer.
5) Results and Discussion
The results of this study’s data can be seen in Figures 2, 3, and 4. The analysis demonstrated
that with a one mile buffer, the majority of the City of Portland has geographic food access with
focal areas of identifiable food deserts labeled in red, as shown in Figures 2 and 3. These grocery
stores appeared to be concentrated in areas with major roadways, with disparities occurring in the
East and Northwest neighborhoods at a 1 mile buffer. The ½ mile buffer demonstrates
concentrations of grocery stores throughout the city with the majority of grocery stores being
within a mile of one another towards the centroid of the city. Areas identified as food deserts in
the ½ mile buffer are shown to gradually increase as they are closed to the periphery of Portland
city limits. Although this study focused on the identification of food deserts, the literature shows

9. that these may be defined broadly or have many parameters. This study’s application of a 1 mile
and ½ mile buffer fits the description of Portland, which is a mixture of urban and suburban
residential areas with easily accessible public transportation in the majority of these areas.
6) Conclusion
This study sought to identify potential food deserts in Portland Oregon while creating zones of
food accessibility based one geographic location and distance. Residents living in the identified
East and Northwest neighborhoods are vulnerable to food disparities. As Portland prides itself in
its establishment of a progressive community, policies for sustainable development for food access
infrastructure can aid in this public health concern. The public transportation system of buses and
metro lines allows for an easier access of food deserts, but quality of available food and prices
were not able to be established within the scope of this study. Further data collection and research
into the subject of food deserts within Portland in the goal for this study. A longitudinal study is
recommend for further insights into the dynamics of food deserts on a case study by case study
basis while considering all factors and parameters.

10. 7) Works Cited
Breyer, B., & Voss-Andreae, A. (2013). Food mirages: Geographic and economic barriers to
healthful food access in Portland, Oregon. Health & Place, 24, 131-139.
http://dx.doi.org/10.1016/j.healthplace.2013.07.008
Gordon, C., Purciel-Hill, M., Ghai, N., Kaufman, L., Graham, R., & Van Wye, G. (2011).
Measuring food deserts in New York City's low-income neighborhoods.Health & Place,
17(2), 696-700. http://dx.doi.org/10.1016/j.healthplace.2010.12.012
LeClair, M., & Aksan, A. (2014). Redefining the food desert: combining GIS with direct
observation to measure food access. Agric Hum Values, 31(4), 537-547.
http://dx.doi.org/10.1007/s10460-014-9501-y
McEntee, J. & Agyeman, J. (2010). Towards the development of a GIS method for identifying
rural food deserts: Geographic access in Vermont, USA. Applied Geography, 30, 165–176.
doi:10.1016/j.apgeog.2009.05.004
Walker, R., Keane, C., & Burke, J. (2010). Disparities and access to healthy food in the United
States: A review of food deserts literature. Health & Place, 16(5), 876-884.
http://dx.doi.org/10.1016/j.healthplace.2010.04.013
Widener, M. J. & Shannon, J. (2014). When are food deserts? Integrating time into research on
food accessibility. Health & Place, 30, 1-3.
http://dx.doi.org/10.1016/j.healthplace.2014.07.011

11. 8) Tables and Figures
Table 1. Data Sources and Layers
Data
Layer
File Name
Export File
Name
File Type Data Resolution Source
Portland
Grocery
Stores
grocery_stor
es_PDX
Grocery
Stores
Vector
Shapefile
(Point)
N/A
Bureau of Planning
and Sustainability
(BPS)
Bus Line
Routes
buslines
Bus Line
Routes
Vector
Shapefile
(Line)
NAD 1983 HARN
StatePlane Oregon North
FIPS 3601 CoordinateSystem
Metro's Regional Land
Information System
(RLIS) Discovery
City
Limits
cty_fill
Portland City
Limit
Vector
Shapefile
(Polygon)
NAD 1983 HARN
StatePlane Oregon North
FIPS 3601 CoordinateSystem
Metro's Regional Land
Information System
(RLIS) Discovery
County
Lines
co_fill
County
Boundaries
Vector
Shapefile
(Polygon)
NAD 1983 HARN
StatePlane Oregon North
FIPS 3601 CoordinateSystem
Metro's Regional Land
Information System
(RLIS) Discovery
Major
River
mjriv_fi Waterbodies
Vector
Shapefile
(Polygon)
NAD 1983 HARN
StatePlane Oregon North
FIPS 3601 CoordinateSystem
Metro's Regional Land
Information System
(RLIS) Discovery
Light
Rail Line
lrt_light
Lightrail
Lines
Vector
Shapefile
(Line)
NAD 1983 HARN
StatePlane Oregon North
FIPS 3601 CoordinateSystem
Metro's Regional Land
Information System
(RLIS) Discovery
Zoning zoning Food Desert
Vector
Shapefile
(Polygon)
NAD 1983 HARN
StatePlane Oregon North
FIPS 3601 CoordinateSystem
Metro's Regional Land
Information System
(RLIS) Discovery

12. Figure 1. Identifying Potential Food Deserts in Portland, OR: Data Manipulation and GIS
operations utilized within this study for food desert identification.

13. Figure 2. Identifying Potential Food Deserts in Portland, OR: A visual depiction of food accessible
areas with a half mile buffer (shown in bright green) with the one mile buffer extension (shown in
pale green) from grocery stores in conjunction with identified food desert areas (shown in red).

14. Figure 3. Identifying
Potential Food Deserts in
Portland, OR (1mi Buffer):
A visual depiction of food
accessible areas with a one
mile buffer from grocery
stores (shown in green) in
conjunction with identified
food desert areas (shown in
red).
Figure 4. Identifying
Potential Food Deserts in
Portland, OR (½mi Buffer):
A visual depiction of food
accessible areas with a half
mile buffer from grocery
stores (shown in green) in
conjunction with identified
food desert areas (shown in
red).