Introduction: Urban gardens are an important source of community empowerment through food secu-rity. The few urban gardens established in San Francisco are not enough to meet the needs of the city’s growing population. Therefore, we seek to determine the best location to site a new urban garden by working with our client, Produce to the People.Produce to the People is a San Francisco organization that works to improve the health and food security of communities through urban gardening. This organization strongly ad-vocates community self-determination over their local food systems, and urban gardening is crucial to this task.Our new garden will be sited in an existing public park. Produce to the People is closely af-filiated with the San Francisco Parks Alliance, which works on projects that increase public park access and enjoyment, such as urban gardens. In order to determine the best park to site our garden, we will consider parks that serve the highest population of residents and which contain the most suitable environmental conditions for growing fresh produce.

Urban Community Garden in San FranciscoLA C188 | Fall 2017 | Sec 104 | Kristen Flores, Yselia Cortez, Kailun Huang

Purpose:Find the best location for an urban commu-nity garden in SFWill site at pub-lic parks

Client:Produce to the People, an or-ganization that works with SF Parks Alliance

Source:1. USGS National Map Viewer2. The California Department of Public Health (CDPH) 3. TIGER/Line with Selected Demograph-ic and Economic Data and U.S. Census 20104. San Francisco Open Data and DataSF5. John Radke GIS data source: network analysis map6. word art, http://wordart.com/create

Methods:1. Raster Surface Modeling - Slope and Aspect : San Francisco contour to generate slope as a constraint factor, and winter solar radiation as a opportunity factor.2. Vector and raster suitability map: use vector tool to manage most social factors such as population and zoning. use raster generated by surface model as natural factors. Then, determined factors that might become opportunity or constrain.3. Network analysis map - Location Allocation: parks were the possible facilities and the highly populated Census tracts were the demands

Raster Surface ModelingIn order to create our two surface maps, we used a 1/9 arc second DEM from the USGS National Map Viewer. Using the raster surface modeling method, we creat-ed two surface models from our elevation data: one for slope and one for aspect. The surface slope map was used to find areas that had a gentle slope (areas with a slope of less than 30 degrees) that would be optimal for creating an urban garden. An area with a slope above 30 degrees would have to be terraced in order to be utilized for gardening. The surface aspect map identifies the areas that will re-ceive the highest amount of solar radiation during the time from October 1st until February 28th. The dark green areas are the most useful for winter gardening be-cause they receive the greatest amount of sunlight during these months.

Winter Solar Radiation on San Francisco

Surface Slope of San Francisco

Vector and Raster Suitability Map

Network Analysis MapTo determine which potential garden site would serve the most people, we conducted a loca-tion-allocation analysis. First, we limited potential sites to Mini Parks, Neighborhood Parks, and Family Camps. This allows us to avoid more highly protected areas, and also focuses our search on more highly populated residential areas. Using data from the 2010 Census, we created a shapefile of the most densely populated Census tracts in San Francisco. These tracts have a pop-ulation of over 4,000 people, which is above the city Average.Using this data, we conducted a location-allocation in which these parks were the possible fa-cilities and the highly populated Census tracts were the demands. We chose to do a “Maximize Attendance” location-allocation in order to determine which park could serve the most people. Based on our analysis, Page and Laguna Mini Park would serve the greatest number of residents and is a promising potential site for our garden. However, our analysis also located 93 other po-tential sites that would serve a high population.

Flow Chart

Population as an opportunity in order to service more people as possible. We choose to clssify the population density, also for getting more support from people. For zoning, since we are sup-ported by parks Alliance, so we think from a policy level, parks or public will be easier to transfer to a urban garden. Meanwhile, industrial land might contain pollution which will affect to food directly, so we value it as a constrain. From the raster map, suitability also imported winter solar radiation as opportunity, and slope as constrain. Maher map is a shapefile of known or potential soil and/or groundwater contamination. Existing grocery store as competors to urban garden, so that we value it as a constrain. To buffer it to a walking distance.

Conclusion:Based on our network analysis and suitability map, we have identified Page and Laguna Mini Park as the most suitable site for an urban gar-den. This site is highly suitable based on our cri-teria. Page and Laguna Mini Park is accessible to the highest population of San Francisco res-idents, and experiences high winter radiation, gentle slope, and no contamination. Therefore, we conclude that this would be an excellent site for San Francisco’s next urban garden.