HEALTHY DEVELOPMENT MEASUREMENT TOOL

Indicator ES.2.b Open space

Descriptive Title: Distribution of open spaces and natural areas

Geographic Unit of Analysis: Open space boundaries

Why Is This An Indicator Of Health and Sustainability?

Parks and natural open space areas promote physical activity and social interaction. Areas with natural vegetation also have direct effects on physical and mental health. One review of studies showed that access to places for physical activity combined with outreach and education can produce a 48% increase in the frequency of physical activity.^a Exposure to greenery and the natural world has additional benefits to health. 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.^b Trees and green space also improve the physical environment by removing air pollution from the air and mitigating the urban heat island effect produced by concrete and glass.^c

Interpretation and Geographic Equity Analysis

Public open space refers to lands that are publicly owned, publicly used, and publicly accessible. The amount of public open space per neighborhood varies greatly across San Francisco. San Francisco’s Golden Gate Park and Presidio neighborhoods have the highest number of acres of public open space per 1,000 residents; but these neighborhoods have very small populations compared to the rest of the city. Other neighborhoods with a large number of acres of public open space per 1,000 residents include Seacliff (127) and Lakeshore (77). According to the National Recreation and Parks Association Guidelines, the national standard acreage of open space is 10 acres per 1,000 people. As a whole, San Francisco is currently below the standard with approximately 8 total acres of open space/1,000 residents. The majority of San Francisco neighborhoods also do not meet the national standard.

The Open Space Element of the City's General Plan (as amended in 1991) requires the City to preserve and protect the Significant Natural Resource Areas (Policy 13). The policy identifies the following criteria used to determine a Significant Natural Area:

1. Relatively undisturbed remnants of San Francisco's original landscape that either support diverse and significant indigenous plant and wildlife habitats or contain rare geologic formations or riparian zones;
2. Sites that contain rare, threatened, or endangered species or areas likely to support these species; and
3. Areas adjacent to other protected natural resource areas.

In San Francisco these communities may include oak woodlands, creeks, lakes, grasslands, dunes, scrub and rock outcrops. In many cases these nature preserves are the only places where wildlife such as the Red-tailed Hawk, Gray Fox, Great-horned Owl, and San Francisco garter snake still reside, reproduce and play.

Methods

To calculate the amount of public open space per 1,000 residents, total acres of open space reported by the San Francisco Department of Parks and Recreation were added with the total acres of open space that are not part of the San Francisco Department of Parks and Recreation per neighborhood and then divided by the total population of the neighborhood to provide the acreage per person of open space for that neighborhood. This figure was then multiplied by 1,000 to create the acres of public open space per 1,000 residents.

Limitations

Acres of significant natural areas alone is not the only measure in appraising a city's natural areas system. Further analysis of San Francisco's natural area system is needed to determine the quality and accessibility of the space. For example, although significant natural areas are present, resources may not be available for its upkeep and maintenance. Not all significant natural areas acreage is accounted for in this data. Significant natural areas not publicly owned have not been accounted for. 

Data Source

Open space area accessed from the San Francisco Planning Department, Summer 2011.

Natural area and acreage accessed from San Francisco Recreation and Park Department, August 6, 2009.

Map and table created by San Francisco Department of Public Health, Environmental Health Section using ArcGIS software. Table data is presented by planning neighborhood. Detailed information regarding census data, geographic units of analysis, their definitions, and their boundaries can be found in the HDMT at the following links:

http://www.thehdmt.org/etc/Geographic_Units_of_Analysis.pdf

http://www.thehdmt.org/data_map_methods.php