The advent of NEHRP in 1977, together with its subsequent reauthorizations, added substantial resources for research in seismology, earthquake engineering, and social sciences with the goal of increasing knowledge for understanding the causes of earthquakes and reducing their impacts. In addition, the program improved coordination among federal government agencies with responsibilities in those areas and promoted integration of research and applications. Moreover, although NEHRP covers only four federal agencies, the program provides a focus for earthquake-related activities of many other federal, state, regional, and local government agencies, and—to some extent—the private sector.
Efforts to understand the causes of earthquakes and to counter their effects certainly did not begin with NEHRP. In the United States, the landmark study of the 1906 San Francisco earthquake (Lawson, 1908) furthered the elastic rebound hypothesis, whereby accumulated strain energy is released suddenly by fault slip, and demonstrated the vulnerability of structure built on soft sediments. Advances in other countries, especially Japan, also contributed new knowledge. Most importantly, developments of plate tectonics concepts in the mid-1960s established an overall framework for understanding the occurrence of earthquakes (and volcanoes) worldwide.
Nevertheless, NEHRP stimulated substantial earthquake research in the United States and, most significantly, integrated the efforts of the various earthquake-related disciplines and organizations toward the goal of reducing earthquake losses. The degree of success of these endeavors is reflected in the impressive list of accomplishments summarized in the
introduction to this report. In view of the important stimulus to earthquake mitigation activities provided by NEHRP and its substantial record of achievements, the committee endorses the 2008 NEHRP Strategic Plan and identifies 18 specific task elements required to implement that plan and materially improve national earthquake resilience.
Defining Earthquake Resilience
A critical requirement for achieving national earthquake resilience is, of course, an understanding of what constitutes earthquake resilience. In this report, we have interpreted resilience broadly so that it incorporates engineering/science (physical), social/economic (behavioral), and institutional (governing) dimensions. Resilience is also interpreted to encompass both pre- and post-disaster actions that, in combination, will enhance the robustness and the capabilities of all earthquake-vulnerable regions of our nation to function well following likely, significant earthquakes. The committee is also cognizant that it is cost-prohibitive to achieve a completely seismically resistant nation. Instead, we see our mission as helping set performance targets for improving the nation’s seismic resilience over the next 20 years and, in turn, developing a more detailed roadmap and program priorities for NEHRP. With these considerations in mind, the committee recommends that NEHRP adopt the following working definition for “national earthquake resilience”:
A disaster-resilient nation is one in which its communities, through mitigation and pre-disaster preparation, develop the adaptive capacity to maintain important community functions and recover quickly when major disasters occur.
No standard metric exists for measuring disaster resilience, and it is clear that standardized methods would be helpful for gauging improvements in resilience as a result of disaster risk reduction planning and mitigation. However, because the concept of resilience is specific to the context of the specific community and its goals, it can be expected that no single measure will be able to capture it sufficiently. No one resilience indicator can suit all purposes, and different measurement approaches may be appropriate in different contexts for assessing current levels of disaster resilience and incremental progress in developing resilience.
Elements and Costs of a Resilience Roadmap
To provide a sound basis for future activities, the NEHRP agencies—under the leadership of the National Institute of Standards and
Technology (NIST) as lead agency—developed a Strategic Plan (Appendix A). The plan, with three major goals and 14 objectives, constitutes a comprehensive, integrated approach to reducing earthquake losses. The committee endorses the elements of the strategic plan—the goals and objectives—and embraces the integrated, comprehensive, and collaborative approach among the NEHRP agencies reflected in the plan. The committee set out to build on the Strategic Plan by specifying focused activities that would further implementation of the plan. In the end, 18 tasks were selected, ranging from basic research to community-oriented applications, which, in our view, comprise a “roadmap” for furthering NEHRP goals and implementing the Strategic Plan. The committee recommends that these tasks be undertaken.
In estimating costs to implement the roadmap, the committee recognizes that there is a high degree of variability among the 18 tasks—some (e.g., deployment of the Advanced National Seismic System Network [ANSS], the Network for Earthquake Engineering Simulation [NEES] earthquake engineering simulation laboratories) are under way or are in the process of being implemented, whereas others are only at the conceptual stage. Costing each task required a thorough analysis to determine scope, implementation steps, and linkages or overlaps with other tasks. For some of the tasks, the necessary analysis had already been completed in workshops or other venues, and realistic cost estimates were available as input to the committee. For other tasks, the committee had nothing more to go on than its own expert opinion, in which case implementing the task may require some degree of additional detailed analysis. In summary, the annualized cost for the first 5 years of the roadmap for national earthquake resilience is $306.5 million/year (2009$), made up of the following tasks:
1. Physics of Earthquake Processes. Conduct additional research to advance the understanding of earthquake phenomena and generation processes and to improve the predictive capabilities of earthquake science; 5-year annualized cost of $27 million/year, for a total 20-year cost of $585 million.
2. Advanced National Seismic System. Complete deployment of the remaining 75 percent of the Advanced National Seismic System; 5-year annualized cost of $66.8 million/year, for a total 20-year cost of $1.3 billion. On-going operations and maintenance costs after the initial 20-year period of $50 million/year.
3. Earthquake Early Warning. Evaluation, testing, and deployment of earthquake early warning systems; 5-year annualized cost of $20.6 million/year, for a total 20-year cost of $283 million.
4. National Seismic Hazard Model. Complete the national coverage
of seismic hazard maps and create urban seismic hazard maps and seismic risk maps for at-risk communities; 5-year annualized cost of $50.1 million/year, for a total 20-year cost of $946.5 million.
5. Operational Earthquake Forecasting. Develop and implement operational earthquake forecasting, in coordination with state and local agencies; 5-year annualized cost of $5 million/year, for a total 20-year cost of $85 million. On-going operations and maintenance costs after the initial 20-year period are unknown.
6. Earthquake Scenarios. Develop scenarios that integrate earth science, engineering, and social science information and conduct exercises so that communities can visualize earthquake and tsunami impacts and mitigate their potential effects; 5-year annualized cost of $10 million/year, for a total 20-year cost of $200 million.
7. Earthquake Risk Assessments and Applications. Integrate science, engineering, and social science information in an advanced GIS-based loss estimation platform to improve earthquake risk assessments and loss estimations; 5-year annualized cost of $5 million/year, for a total 20-year cost of $100 million.
8. Post-earthquake Social Science Response and Recovery Research. Document and model the mix of expected and improvised emergency response and recovery activities and outcomes to improve pre-disaster mitigation and preparedness practices at household, organizational, community, and regional levels; 5-year annualized cost of $2.3 million/year, reviewed after the initial 5-years.
9. Post-earthquake Information Management. Capture, distill, and disseminate information about the geological, structural, institutional, and socioeconomic impacts of specific earthquakes, as well as post-disaster response, and create and maintain a repository for post-earthquake reconnaissance data; 5-year annualized cost of $1 million/year, for a total 20-year cost of $14.6 million. On-going operations and maintenance costs after the initial 20-year period are unknown, but are likely to be small.
10. Socioeconomic Research on Hazard Mitigation and Recovery. Support basic and applied research in the social sciences to examine individual and organizational motivations to promote resilience, the feasibility and cost of resilience actions, and the removal of barriers to successful implementation; 5-year annualized cost of $3 million/year, for a total 20-year cost of $60 million.
11. Observatory Network on Community Resilience and Vulnerability. Establish an observatory network to measure, monitor, and model the disaster vulnerability and resilience of communities, with a focus on resilience and vulnerability; risk assessment, perception, and management strategies; mitigation activities; and reconstruction and recovery; 5-year
annualized cost of $2.9 million/year, for a total 20-year cost of $57.3 million. On-going operations and maintenance costs after the initial 20-year period are unknown.
12. Physics-based Simulations of Earthquake Damage and Loss. Integrate knowledge gained in Tasks 1, 13, 14, and 16 to enable robust, fully coupled simulations of fault rupture, seismic wave propagation through bedrock, and soil-structure response, to compute reliable estimates of financial loss, business interruption, and casualties; 5-year annualized cost of $6 million/year, for a total 20-year cost of $120 million.
13. Techniques for Evaluation and Retrofit of Existing Buildings. Develop analytical methods that predict the response of existing buildings with known levels of reliability based on integrated laboratory research and numerical simulations, and improve consensus standards for seismic evaluation and rehabilitation; 5-year annualized cost of $22.9 million/year, for a total 20-year cost of $543.6 million.
14. Performance-based Earthquake Engineering for Buildings. Advance performance-based earthquake engineering knowledge and develop implementation tools to improve design practice, inform decision-makers, and revise codes and standards for buildings, lifelines, and geo-structures; 5-year annualized cost of $46.7 million/year, for a total 20-year cost of $891.5 million.
15. Guidelines for Earthquake-Resilient Lifeline Systems. Conduct lifelines-focused collaborative research to better characterize infrastructure network vulnerability and resilience as the basis for the systematic review and updating of existing lifelines standards and guidelines, with targeted pilot programs and demonstration projects; 5-year annualized cost of $5 million/year, for a total 20-year cost of $100 million.
16. Next Generation Sustainable Materials, Components, and Systems. Develop and deploy new high-performance materials, components, and framing systems that are green and/or adaptive; the 5-year annualized cost of $8.2 million/year, for a total 20-year cost of $334.4 million.
17. Knowledge, Tools, and Technology Transfer to/from the Private Sector. Initiate a program to encourage and coordinate technology transfer across the NEHRP domain to ensure the deployment of state-of-the-art mitigation techniques across the nation, particularly in regions of moderate seismic hazard; 5-year annualized cost of $8.4 million/year, for a total 20-year cost of $168 million.
18. Earthquake-Resilient Community and Regional Demonstration Projects. Support and guide community-based earthquake resiliency pilot projects to apply NEHRP-generated and other knowledge to improve awareness, reduce risk, and improve emergency preparedness and recovery capacity; 5-year annualized cost of $15.6 million/year, for a total 20-year cost of $1 billion.
Timing of Roadmap Components
The committee recommends that all the tasks identified here be initiated immediately, contingent on the availability of funds, and suggests that such an approach would represent an appropriate balance between practical activities to enhance national earthquake resilience and the research that is needed to provide a sound basis for such activities. The committee also notes that the two “observatory” elements of the roadmap, Task 2 and Task 11, will provide fundamental information to be used by numerous other tasks.
However, at a lower component level within individual tasks, there are some elements that should be implemented and/or initiated immediately whereas others will have to await the results of earlier activities. The need for sequencing individual task components is most clearly expressed in the detailed breakdowns for Tasks 13, 14, and 16, as described in Tables E.5, E.7, and E.9 respectively. For example, the component to develop reliable tools for collapse computations within Task 13 includes scoping studies, a workshop, and development of a work-plan in year 3 that would be followed by experimentation using NEES facilities on critical components of framing systems in years 4-7, experimentation using NEES facilities and E-Defense on multiple framing systems to collapse in years 6-10, and concurrent development of improved hysteretic models of structural components through failure in years 4-20, understanding of the triggers for collapse of framing systems in years 6-10, improved system-level collapse computations and FE codes in years 6-15, validation of improved computational procedures using NEES facilities and E-Defense in years 11-20, as well as 5-yearly syntheses of results and preparation of technical briefs.
Earthquake Resilience and Agency Coordination
It is important to recognize that the four NEHRP agencies, although comprising a critical core group for building earthquake knowledge, constitutes only part of the national research and application enterprise. For example, the National Science Foundation (NSF) part of NEHRP includes only earthquake engineering and social sciences, viewed by NSF as “directed” research, whereas highly relevant earthquake knowledge also comes from “non-directed” research programs in NSF. In the applications area, virtually every agency that builds or operates facilities contributes to the goals of NEHRP by adopting practices or codes to reduce earthquake impacts. These agencies include the U.S. Army Corps of Engineers and the Departments of Transportation, Energy, and Housing and Urban Development. Beyond the role of the federal agencies, government agencies at all levels similarly play a critical role in application of earthquake
knowledge, as does the private sector, especially in the area of building design. Altogether, the contributors to reducing earthquake losses constitute a complex enterprise that goes far beyond the scope of NEHRP. But NEHRP provides an important focus for this far-flung endeavor. The committee considers that an analysis to determine whether coordination among all organizations that contribute to NEHRP could be improved would be useful and timely.
Implementing NEHRP Knowledge
The United States had not experienced a great earthquake since 1964, when Alaska was struck by a magnitude-9.2 event. The damage in Alaska was relatively light because of the sparse population. The 1906 San Francisco earthquake was the most recent truly devastating U.S. shock, as recent destructive earthquakes have been only moderate in size. Consequently, a sense has developed that the country can cope effectively with the earthquake threat and is, in fact, “resilient.” However, coping with moderate events may not be a true indicator of preparedness for a great one, as demonstrated by Hurricane Katrina. The central United States last experienced a devastating sequence of great earthquakes in 1811-1812 in the Mississippi Valley area centered on New Madrid, MO. The East Coast was shocked in 1886 by an earthquake near magnitude-7 at Charleston, SC. These events are now far from the consciousness of the public, and little has been done to prepare for similar events in these regions in the future. The committee believes that efforts should be expanded to anticipate the effects and disruptions that could be caused by a great U.S. earthquake, especially an event in the central or eastern United States where little preparation has been undertaken.
Most critical decisions that reduce earthquake vulnerability and manage earthquake risk are made in the private sector by individuals and companies. The information provided by NEHRP, if made available in an understandable format, and accompanied by diffusion processes, can greatly assist citizens in their decision-making. For example, maps of active faults, unstable ground, and historic seismicity can influence where people choose to live, and maps of relative ground shaking can guide building design.
NEHRP will have accomplished its fundamental purpose—an earthquake-resilient nation—when those responsible for earthquake risk and for managing the consequences of earthquake events use the knowledge and services created by NEHRP and other related endeavors to make our communities more earthquake resilient. Resiliency requires awareness of earthquake risk, knowing what to do in response to that risk, and doing it. But providing information is not enough to achieve resilience—the
diffusion of NEHRP knowledge and implementation of that knowledge are necessary corollaries. Successfully diffusing NEHRP knowledge into communities and among the earthquake professionals, state and local government officials, building owners, lifeline operators, and others who have the responsibility for how buildings, systems, and institutions respond to and recover from earthquakes, will require a dedicated and strategic effort. This diffusion role reflects the limited authority that resides with federal agencies in addressing the earthquake threat. Local and state governments have responsibility for public safety and welfare, including powers to regulate land use to avoid hazards, enforce building codes, provide warnings to threatened communities, and respond to an event. The goals and objectives of NEHRP are aimed at supporting and facilitating measures to improve resilience through private owners and businesses, and supporting local and state agencies in carrying out their duties. Although implementing NEHRP knowledge must move ahead expeditiously, it is also essential that the frontiers of knowledge be advanced in concert, requiring that improving understanding of the earthquake threat, reducing risk, and developing the processes to motivate implementation actions, should all be continuing endeavors.