Tsunami Hazard Areas of Evacuation for the State of California: Community Directed, Humboldt County
Abstract
The entire California coast is susceptible to tsunami inundation from either local or distant sources. To meet the needs of coastal residents and visitors and to help communities become more resilient to natural hazards, the California Geological Survey (CGS), the California Governor's Office of Emergency Services (CalOES), and local stakeholders are collaborating to prepare a statewide tsunami hazard area of evacuation. Updates to the tsunami hazard modeling in California, including inundation mapping for emergency planning, provide new details that better inform and constrain evacuation areas.
Previous evacuation area mapping, "tsunami hazard zones," were developed in Humboldt County by the Redwood Coast Tsunami Work Group (RCTWG) in a region susceptible to a large offshore event along the Cascadia subduction zone. This was the first effort in the state to prepare evacuation maps that are used to educate the public about tsunami hazards along coastal northern California. These initial tsunami evacuation planning, procedures, messaging, and education efforts were informed by tsunami inundation models and maps published by CGS and CalOES in 2009. For this updated effort, we adopt the community-based methods used for the first generation of evacuation maps. We first use the 2009 tsunami inundation maps for emergency planning, along with new tsunami modeling updates to these inundation areas, as a minimum spatial constraint for evacuation areas. We use professional judgement to place the evacuation line landward of the inundation line in a conservative manner. We hold several meetings with the RCTWG Tsunami Mapping Subcommittee to review these updates in the office and in the field. The Humboldt County Office of Emergency Services is then consulted to incorporate their needs for evacuation planning. This is followed by a workshop with the larger community of decision-makers including tribal representatives, city and county planners, local emergency planners, state and federal agencies, and other stakeholders in the community. Once adopted by the community, these new map products will be used by the RCTWG to update their evacuation maps and brochures.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMNH34A..01D
- Keywords:
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- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 4333 Disaster risk analysis and assessment;
- NATURAL HAZARDS;
- 4341 Early warning systems;
- NATURAL HAZARDS;
- 4564 Tsunamis and storm surges;
- OCEANOGRAPHY: PHYSICAL