Prioritizing Sea level riSe adaPtion in San Mateo CountyCY PLAN 204C - Alec Gletzer, Alexis Schäffler, Toni Toscano

[2] Network AnalysisA service area analysis was performed to show areas with longer travel times from emergency services. The locations that were loaded to facilities included the geocoded emergency service points, with a travel time of 2, 4, 6, 8 minutes. Merged polygons were created based on minutes away from emergency services. The final step involved weighting polygons based on travel time from the emergency facility and added this weight as a new field for use in the suitability analysis.

ConclusionPriority areas for sea level rise adaption include East Palo Alto, Foster City and South San Francisco. However, vulnerability to sea level rise is a complex phenomenon, affected by dynamic physical conditions such as tidal fluctuations, and erosion; the status of infrastructure networks and; socio-economic factors such as poverty and accessibility to response services. These factors emphasize the importance of analyzing the localized effects of climate change, although the causes may be global.

It is clear that many of the communities directly adjacent to the shorezone edge are vulnerable to sea level rise by implication of their location. This inherent vulnerability is exacerbated if communities experience more concentrated poverty and are located further away from emergency services.

IntroductionCoastal hazards due to climate change threaten many communities around the world. In addition to incremental inundation over time, these communities are also at risk of disruption from 100-year storm events, which may increase inherent vulnerabilities of living close to the shorline. This analysis examined vulnerability to sea level rise in San Mateo County with a specific focus on bayside communities.

Problem statementA number of factors may make certain communities more vulnerable to sea level rise than others. Therefore, a critical challenge for decision-makers is how to prioritize investments for sea level rise adaptation.

Research questionWhich communities along San Mateo’s County’s shore zone should be prioritized for sea level rise adaptation in terms of the following factors affecting their vulnerability?

- Income- Proximity to emergency services- Public housing

There are various definitions of vulnerability. Our analysis defines vulnerability as the ability of a community to adapt to sea level rise given income status, proximity to emergency services and housing status.

[3] Suitability AnalysisTo perform our suitability analysis, we added the weights for our respective net-work analyses. The analysis also added the public housing and poverty percent-age layers, and weighted these in addition to the network analysis polygons. This resulted in four shapefile categories: (1) three network analysis polygons, (2) buf-fers around the geocoded public housing locations, (3) the area affected by the 100 year flood at 140cm sea level rise, and (4) areas with poverty percentages over 18%. These shapefiles were merged and a new field was added to this merged lay-er to determine the areas with the highest weights, which were unionized. The ar-eas with the highest weights, i.e. the darkest areas, are deemed priority areas for sea level rise adaptation.

[1] Geo-codingGeo-coded San Mateo County public housing locations as well as the following emergency service facilities: fire stations, police stations and medical facilities.

Geo-referenced poverty percentages for San Mateo from the 2000-2011 American Community Survey (ACS) 5 year estimates of Block Group Data for California. This data was used to map the percentage of poverty experienced by a household, defined by the ACR as the count of houses under the poverty line. This equates to the poverty status divided by total number of households. The poverty brackets were mapped using natural breaks and we selected 18% and over as our focus group, i.e. those households most severely impacted by poverty.

Legend

Police Station

Fire Station

Medical Center

Public Housing

Percent Household Below Poverty Line

0%-3%

3.1%-9%

9.01%-17%

17.1%-26%

26.1%-43%

Legend

Fire Station

2 min. travel time

4 min. travel time

6 min. travel time

8 min. travel time

Legend

2 min. travel time

4 min. travel time

6 min. travel time

8 min. travel time

Medical Center

Legend

2 min. travel time

4 min. travel time

6 min. travel time

8 min. travel time

Police Station

Legend

Low Priority Area

High Priority

South San Fancisco

Foster City

East Palo Alto

Area’s innundated along the San Mateo County’s bay shore zone during a 100

year flood in the year 2100.

ReferencesBiging, Greg S., John D. Radke, and Jun Hak Lee (University of California, Berkeley). 2012. Impacts ofPredicted Sea‐Level Rise and Extreme Storm Events on the Transportation Infrastructure in the SanFrancisco Bay Region. California Energy Commission. Publication number: CEC‐500‐2012‐040.Radke. J. 2014. Network analysis data.San Mateo County (SMC). 2001. San Mateo County Human Services Agency’s Affordable HousingChart. [Online]. Available: http://www.co.sanmateo.ca.us/hsa.dir/rentlist_jan2001.htm [23 April2010].San Mateo County (SMC). 2013. [Online]. Public, Non-Profit, and Private Service Locations. [Online]. Available: https://data.smc-gov.org/Government/Public-Non-Profit-and-Private-Service-Locations/iytx-vyie [1 May 2014]. United States Census Bureau. 2014. TIGER/Line® Shapefiles Pre-joined with Demographic Data. [Online]. Available: https://www.census.gov/geo/maps-data/data/tiger-data.html [1 May 2014].