Geoscience Reference
In-Depth Information
2009a). The need for best practices or standards for evacuation map preparation was also
noted in the 2007 NTHMP ive-year review. These guidelines or best practices need to be based
on an evaluation of how people process the maps and what conventions are most effective.
Conclusion: Evacuation maps are critical tools for understanding and communicating
population vulnerability to tsunamis. Most at-risk communities in the Paciic states (Hawaii,
Alaska, Washington, Oregon, and California) and Puerto Rico have produced evacuation
maps with a single line indicating a worst-case scenario, except for Cannon Beach, Oregon,
where the map includes evacuations zones for far- and near-ield tsunamis. Approaches
to evacuation map production vary greatly among NTHMP members (e.g., format, choice
of scenarios); therefore, at-risk populations are expected to interpret different state-
developed representations of tsunami risk. It is unclear whether current evacuation maps
are suficient for enabling effective evacuations or preparing the public due to the absence
of uniform quality standards, evaluative metrics, or guidelines on what constitutes effective
mapping approaches.
Recommendation: The NTHMP Mapping and Modeling Subcommittee should develop
guidelines on evacuation map production that foster consistency in format and quality
across the nation and that are based on sound cartographic principles, although map
content must be tailored to the relevant facilities, populations, and characteristics of the
local communities. To improve public access to evacuation maps, the NTHMP should
develop a national, online repository for tsunami evacuation maps and host a consistent
online mapping application for all tsunami evacuation zones across the United States. The
NTHMP should annually update the inventory of evacuation maps relative to the number
of at-risk communities.
VULNERABILITY ASSESSMENTS
Societal vulnerability to tsunamis refers to the physical, social, economic, and environ-
mental conditions or processes that increase the potential for individuals or communities to
incur losses or damages from future tsunamis (International Strategy for Disaster Reduction,
2004). Common elements of vulnerability within the natural hazard literature include exposure,
sensitivity, and resilience (Dow, 1992; Hewitt, 1997; Cutter, 2003; Turner et al., 2003). Exposure
refers to hazard proximity, sensitivity refers to differential degrees of potential harm given simi-
lar exposure (e.g., different building types), and resilience addresses the coping and adaptive
capacities of an individual or community during and after an extreme event. Understanding
societal vulnerability to tsunamis provides emergency managers with the required information
to protect their communities and to determine whether individuals have the capacity to take
protective actions.
Although this information is considered critical to reducing tsunami risk, until recently rela-
tively little has been written about societal vulnerability to tsunamis compared to the amount
Search WWH ::




Custom Search