Descriptive Title: A relative measure of the number of acres of public recreation space within two miles, weighted by distance.
Geographic Unit of Analysis: Intersection (point)
|Distance weighted two-mile recreational area resource score (2011)|
|Financial District/South Beach||17|
|Golden Gate Park||NA|
|South of Market||25|
|West of Twin Peaks||73|
A review of studies showed that access to places for physical activity combined with outreach and education can produce a 48 percent increase in the frequency of physical activity.a Evidence also shows that contact or views of the natural environment can improve functioning in children with Attention Deficit and Hyperactivity Disorder (ADHD) and problem solving and cognitive function in people living in public housing.b,c More generally, living in proximity to green space is associated with reduced self-reported health symptoms, better self-rated health, and higher scores on general health questionnaires.d Finally, children who live in close proximity to parks, playgrounds, and recreational facilities tend to be more active compared to children who do not live near those facilities.e Adolescents who engage in moderate physical activity five or more times a week are more likely to achieve an ‘A’ in math and science than their peers.f
The Public Recreational Area Resource Indicator is a measure of access to acres of public recreational space. Public recreational space includes public parks, natural areas, and recreation centers. These spaces are primarily owned and maintained by the San Francisco Recreation and Parks Department, but other agencies such as the National Parks Service, the State of California, the Port, the Public Utilities Commission, and the Department of Public Works also own some of the spaces included in this analysis. Scores were determined by summing the total acres of all parks within two miles of an intersection and applying a distance penalty if the park was a half mile or more away from the intersection.
Largely due to the presence of Golden Gate Park, the Presidio, the Golden Gate National Recreation Area, and Lake Merced Park, the western side of the city has access to significantly more public recreation acres than the eastern side of the city. Parkside and Inner Richmond have the highest Public Recreation Access Scores because they are within two miles of numerous large recreational spaces. The City’s eastern neighborhoods, particularly the Treasure Island, Mission Bay, South of Market, Potrero Hill, Financial District, Chinatown, and North Beach neighborhoods, have lower Access Scores because they are far from the City’s large recreation areas. Many of these eastern neighborhoods have some of the highest population densities in the city and are slated for significant residential growth over the next few decades, in the cases of South of Market, Mission Bay, and Treasure Island. While high population density means increased demand for green space, it also often means that land for recreational spaces is limited.
A revised addition of the Recreation and Open Space Element (ROSE) of the San Francisco General Plan will be released in 2012 and will plan for additional recreation land acquisition and improvements to existing recreation areas. Based on the San Francisco Planning Department’s analysis of existing resources and the distribution of children, seniors, and low income households, areas in Chinatown, North Beach, Mission Bay, and Treasure Island have been identified as priority renovation and acquisition areas (http://openspace.sfplanning.org/). Parts of the Mission, Bayview, and Crocker Amazon have also been identified as priority areas in the ROSE.
To calculate the Public Recreational Area Resource Scores, the distance from each residential intersection (intersections within 100 meters of residential lots) to recreation spaces (park, natural area, or recreation center) within 2 miles of the intersection was calculated. A distance of < 0.5 miles was given a score of 1, while distances between 0.5-1 miles were given a score of 0.75 and distances >1-2 miles were given a score of 0.5.
In order to make sure that large parks in the city, such as Golden Gate Park and the Presidio, did not overly skew the distribution of relative access to recreation spaces, a formula for diminishing returns was applied to each park’s acreage. The assumption was, that as a park’s acreage becomes increasingly large, additional acres add less and less value. Thus, the formula used was:
Diminishing Return Adjusted Acreage = (actual acreage x acreage cap)/(actual acreage + acreage cap)
An acreage cap of 250 acres was chosen because parks of 250 acres or more are in the largest park category of regionally serving parks, as specified by the National Recreation and Parks Association. Thus, additional acres could not advance a park of 250 acres or more into a higher category and would not add significantly more value.
Distance weights were then multiplied by the diminishing returns adjusted acreage for each recreation space within the 2 mile search radius. These products were then summed for each intersection, for a sum of “distance weighted acres.” The distance weighted acres for each intersection were then normalized to a scale of 0-100 to create a Public Recreational Area Resource Score.
Public Recreational Area Resource Scores for all of the residential intersections in the city were interpolated onto a continuous surface in ArcGIS using an inverse distance weighting (IDW) technique, with an output cell size of 30 and a variable search radius that sampled the 12 nearest points.
Neighborhood averages were calculating by taking the average of the Public Recreational Area Resource Scores for all of the intersections that fell within a neighborhood.
The analysis here relies on total accessible acreage as a measure of public recreation space quality. However, the quality and utility of recreational spaces is influenced by many other factors beyond land area, including the range of facilities, like playgrounds, sports fields/courts, swimming pools, bathrooms, etc., and the safety and cleanliness of the space. Many of the small parks included in this analysis may have numerous high quality facilities, while some of the larger parks may be relatively unimproved or poorly maintained. It is hoped that future iterations of this indicator will be able to incorporate the breadth of available amenities in the Resource Score.
Additionally, many other factors besides distance influence the accessibility of a recreational space, such as the presence of major roads, highways, buildings, steep hills, and gates; one’s mobility status; and whether a neighborhood is safe enough to travel through.
In December 2003, the Neighborhood Parks Council released a report titled Green Envy: Achieving Equity in Open Space, which highlights disparities in neighborhood access to quality parks and open space. The report provides additional maps and resources to examine proximity and accessibility of parks in San Francisco, as well as a critique of San Francisco's commitment to promoting open space. For more information, see: http://www.sfnpc.org/greenenvy
List of parks, natural areas, and recreation centers from the San Francisco Planning Department, 2011.
San Francisco street intersections (published May 4, 2010), San Francisco Department of Public Works. Accessed July 2011. Available at: http://gispub02.sfgov.org/website/sfshare/index2.asp.
2010 US Census.
Map and table prepared by City and County of San Francisco, Department of Public Health, Environmental Health Section using ArcGIS software.
Map data is analyzed at the intersection level and table data are presented by planning neighborhood.
Taylor AF, Kuo FE, Sullivan WC. Coping With ADD: The Surprising Connection to Green Play Settings. Environment and Behavior. 2001;33(1) 54-77.
Kuo FE. Coping With Poverty Impacts of Environment and Attention in the Inner City. Environment and Behavior. 2001;33(1):5-34.
Bauman A, Bull F. Environmental Correlates of Physical Activity and Walking in Adults and Children: A Review of Reviews. London: National Institute of Health and Clinical Excellence; 2007.
Nelson MC, Gordon-Larsen P. Physical activity and sedentary behavior patterns are associated with selected adolescent health risk behaviors. Pediatrics. 2006;117:1281-1290.