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The Current and Future Impact of Community Gardens in the City of BerkeleyYvonne Chan Benjamin Kopania Jie Zhou Dec 8th, 2017
LD ARCH & GEOG C188 Final ProjectInstructor: Prof. John Radke GSI: Michelle Wray Nimisha Wasankar Yang Liu
Introduction Our client is the Berkeley Food Institute (BFI), a local organization that seeks to expand access to fresh food while promoting sustain-able and equitable food production. These goals require that current food systems are transformed to cultivate alternative and regionalized “agri-food networks” that increase local food sovereignty. One prima-ry objective of the BFI is to fill existing gaps of knowledge through re-search in order to inform policymakers. This project seeks to aid the BFI in their research by performing an analysis that will demonstrate the current and potential future impact of community gardens in serv-ing the demand for local food in Berkeley.
Image Resource: https://inhabitat.com/tag/sustainable-farming/
Data Discovery DEM
VectorSoil TypeDisadvantage CommunitiesBike?Streets?Parks?DensityLanduse
Toxic SitesLandslidesSoil?
Contour Lines
Service Area Analysis
Export Service Area Polygons
Location Alloca-tion Analysis
Load Berkeley Network
Load Locations of Existing Gardens
TIN Model
Gentle Slope
Add Weight
Add Weight
Add Weight
Union
Union
Union
Opportunities Factors
Constraints Factors
Composite Opportunities Map
Suitability Map
Drape on TIN Model
Select Best Sites
Location Alloationwith Existing gradens
Maxium Market Share
Maxium Market Share
Calculate % of Populatin ServedCurrent % of
Populatin Served
Composite Constraints MapSteep Slope
Data Discovery DEM
VectorFertile SoilDisadvantage CommunitiesBike BovelavardStreets ProximityParks ProximityDensity AreaLanduse
Toxic SitesLandslidesInfertile Soil
Contour Lines
Service Area Analysis
Export Service Area Polygons
Location Alloca-tion Analysis
Load Berkeley Network
Load Locations of Existing Gardens
TIN Model
Gentle Slope
Add Weight
Add Weight
Union
Union
Union
Opportunities Factors
Constraints Factors
Composite Opportunities Map
Suitability Map
Drape on TIN Model
Select Best Sites
Location Allocationwith Existing gradens
Maximum Market Share
Maximum Market Share
Calculate % of Population ServedCurrent % of
Population Served
Composite Constraints MapSteep Slope
Constraints
Layer Constraint Weight
Toxic Sites 500 ft buffer -3
Steep Slopes Slopes > 8.5 degrees -2
Landslides 100 ft buffer -1
Current Gardens Within 1 minute service area -2
Soil Unsuitable for Farming (Vertisols)
-1
Opportunities
Layer Opportunity Weight
Gentle Slopes Slopes <= 5 degrees 1
Soil Fertile Soils (Alfisols and Mollisols)
1
Bicycle Boulevards 300ft Buffer 1
Streets 100ft Buffer 1
Parks 500ft Buffer 1
Population Density Greater than 15000, 500ft Buffer
1
Disadvantaged Communities CalEnviroScreen disadvantage percentile 1-30% (lowest scores), 31-55%, 56-80%
0, 1, 2
Landuse Vacant residential and commercial lots
2
Constraints
Layer Constraint Weight
Toxic Sites 500 ft buffer -3
Steep Slopes Slopes > 8.5 degrees -2
Landslides 100 ft buffer -1
Current Gardens Within 1 minute service area -2
Soil Unsuitable for Farming (Vertisols)
-1
Opportunities
Layer Opportunity Weight
Gentle Slopes Slopes <= 5 degrees 1
Soil Fertile Soils (Alfisols and Mollisols)
1
Bicycle Boulevards 300ft Buffer 1
Streets 100ft Buffer 1
Parks 500ft Buffer 1
Population Density Greater than 15000, 500ft Buffer
1
Disadvantaged Communities CalEnviroScreen disadvantage percentile 1-30% (lowest scores), 31-55%, 56-80%
0, 1, 2
Landuse Vacant residential and commercial lots
2
Opportunities WeightConstraints Weight
_̂_̂
Datum & Projection: NAD83 CA State Plane Zone IIIDate: December 8, 2017
Authors: BK, YC, JZ
Berkeley Urban Gardens Suitability AnalysisGarden Opportunities
_̂ Most Suitable Sites
Berkeley BoundaryGardens_SuitabilityTotal Weight
-5-4-3-2-10123456789 Ü0 0.7 1.4 2.1 2.80.35
Miles
!8
!8
!8
!8
!8!8
Datum & Projection: NAD83 CA State Plane Zone IIIDate: December 8, 2017
Authors: BK, YC, JZ
Ü
Potential Market Share of Existing and Proposed Gardens
Berkeley Gardens & Demand
!8 Existing and Potential Gardens
Demand Lines
Demand Points
Berkeley boundary
0 0.7 1.4 2.1 2.80.35Miles
!8
!8
!8
!8
Datum & Projection: NAD83 CA State Plane Zone IIIDate: December 8, 2017
Authors: BK, YC, JZ
Ü
Market Share of Existing GardensBerkeley Gardens & Demand
!8 Existing Gardens
Demand Lines
Demand Points
Berkeley boundary
0 0.7 1.4 2.1 2.80.35Miles
Problem Statement In our analysis, we aim to find the most suitable locations in Berke-ley for new community gardens, approximate the current market share of existing gardens in Berkeley, and calculate the market share increase that would result by the addition of new gardens. In order to define and select “suitable” locations, we combined a mixture of geo-physical, urban design, and demographic variables to pragmatically and equitably cite new garden locations.
MethodsWe achieved this through three modeling techniques:
1)TIN Model• Created a TIN model from USGS digital elevation model• Utilized model to calculate slope as a variable for an opportunity
and constraint layer
Datum & Projection: NAD83 CA State Plane Zone IIIDate: December 8, 2017
Authors: BK, YC, JZ
Berkeley Urban Gardens Composite Constraints
Garden ConstraintsBerkeley Boundary
constaint weight-7-6-5-4-3-2-10
Ü 0 0.7 1.4 2.1 2.80.35Miles
Datum & Projection: NAD83 CA State Plane Zone IIIDate: December 8, 2017
Authors: BK, YC, JZ
Berkeley Urban Gardens Composite Opportunities
Garden OpportunitiesBerkeley Boundary
Opportunities Weight123456789
Ü 0 0.7 1.4 2.1 2.80.35Miles
Findings and ConclusionCurrent population of Berkeley served by existing community gardens (%): 20.6%Potential population served by existing and proposed gardens (%): 30.9%Potential increase in access to gardens (%): 10.3%
With a potential 10% increase of individuals with access (here defined as within a 1-minute impedance area) to com-munity gardens, our findings suggest that there remains significant work in order for the City of Berkeley to enable its residents to have more sovereignty and control over city-grown food. Due to the city’s growing population and increasing density, it is vital that residents have access to green space; not only can this green space serve recreational purpos-es, but it can also enable vulnerable communities to affordably access nutritious food. We have concluded that with the space limitations of Berkeley, improving the transportation network, and thus accessibility, of the city could significantly increase the accessibility of community gardens.
Limitations:The primary limitations of our analysis were online access to geographic data and accuracy of impedance timing of the Berkeley network. Additional community engagement is also necessary to confirm the suitability of our selected sites.
For our initial market share analysis we used an im-pedance of 1 minute, which corresponded to our con-straint weight factor for the 1 minute service area of existing gardens. The resulting market share percent-age was 20.6%.
For our final market share analysis we included the orig-inal existing gardens and the two most suitable sites. The resulting market share percentage was 30.9%.
The results of our suitability analysis showed two sites in Berkeley that were the most suitable, as symbolized by the blue stars. We then used the feature to point tool to convert the top two sites to points in order to perform a loca-tion-allocation network analysis on them.
2) Composite suitability map• Utilized ArcGIS proximity tools to process opportunity and constraint factor layers• 3) Service area and point-to-point location allocation network analyses • Performed service area network analysis with an impedance of 1 minute intervals to generate a
constraint layer that will keep our selected sites out of the service area of current gardens• Performed location-allocation analysis to calculate market share of existing gardens • Performed location-allocation analysis to calculate total market share of current and proposed gar-
dens
Suitability Analysis
Network Analysis
Flow Chart
TIN Model
Data Sources:CalEnviroScreen Disadvantaged Communities:https://oehha.ca.gov/calenviroscreen/report/calenviroscreen-30
National Cooperative Soil Survey: https://www.arcgis.com/home/item.html?id=40778f761b8845e29c3eae8016404957
City of Berkeley Open Data Portal: https://data.cityofberkeley.info/browse?limitTo=maps&utf8=%E2%9C%93
USGS National Map Viewer: https://viewer.nationalmap.gov/basic/
Berkeley Existing Garden Locations:https://communitygarden.org/find-a-garden/?garden-search=Berkeley&distance=100
LD ARCH/GEOG C188 Labs 3 & 7 geodatabases and Berkeley/Oakland network
Legendno_aspect_suit_testsuit_wt
-5
-4
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-1
0
1
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