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Pedestrian tsunami evacuation results for three California probabilistic tsunami hazard zones and four travel speeds (shapefiles) and impaired walk travel times for all zones by parcel land-use and flow depth class (tables)

August 12, 2020

These datasets supports the conclusions in the journal article entitled "Variations in community evacuation potential related to average return periods in probabilistic tsunami hazard analysis" as described in the abstract below:

Tsunami risk management requires strategies that can address multiple sources with different recurrence intervals, wave-arrival times, and inundation extents. Probabilistic tsunami hazard analysis (PTHA) provides a structured way to integrate multiple sources, including the uncertainties due to the natural variability and limited knowledge of sources. PTHA-based products relate to specific average return periods (ARP) and while there has been considerable attention paid to ARP choice for building codes, guidance on ARP choice to support evacuation planning and related land-use is lacking. We use the State of California (USA) coastal communities as a case study to explore the use of geospatial analysis and pedestrian-evacuation modeling for comparing the societal implications of tsunamis based on evacuation areas that reflect 475-year, 975-year, and 2,475-year ARPs. Results demonstrate that changes in PTHA ARP had a substantial effect on the number of taxlot parcels in tsunami evacuation areas, but not on the primary land-use of these parcels or which communities had the highest number of exposed parcels. Composite PTHA maps provided high-level insights on hazard exposure and identified dominant sources; however, disaggregated PTHA outputs that reflect single source parameters (e.g., wave-arrival time) were necessary to quantify evacuation potential from local and distant tsunamis. Framing changes in ARP assumption based on changes in the number, land-use type, and potential evacuation challenges of parcels in evacuation areas can provide valuable insight on the real-world implications of which ARP to use in land-use or evacuation planning.

These data support the following publication: Wood, N., Peters, J., Wilson, R., Sherba, J., and Henry, K., 2020. Variations in community evacuation potential related to average return periods in probabilistic tsunami hazard analysis. International Journal of Disaster Risk Reduction.