Laurie A. Johnson, PhD, AICP
Principal, Laurie Johnson Consulting | Research
This paper is prepared for the National Science Foundation–sponsored, and National Research Council–led, Community Workshop to describe the Grand Challenges in Earthquake Engineering Research, held March 14–15, 2011, in Irvine, California. It offers ideas to help foster workshop discussions on transformative earthquake engineering research and achieving earthquake resilience in communities. Over the next 50 years, America’s population will exceed 400 million, and much of it will be concentrated in the earthquake-prone, mega-regions of the Northeast, Great Lakes, Pacific Northwest, and northern and southern California. To achieve an earthquake-resilient nation, as envisioned by the National Earthquake Hazards Reduction Program, earthquake professionals are challenged to strengthen the physical resilience of our communities’ buildings and infrastructure while simultaneously addressing the environmental, economic, social, and institutional resilience of these increasingly dense, complex, and interdependent urban environments. Achieving community resilience will require a whole host of new, innovative engineering solutions, as well as significant and sustained political and professional leadership and will, an array of new financial mechanisms and incentives, and concerted efforts to integrate earthquake resilience into other urban design and social movements.
There is tremendous need and opportunity for networked facilities and cyberinfrastructure in support of basic and applied research on community resilience. Key ideas presented in this paper include developing better models of community resilience in order to establish a baseline and to measure resilience progress and effectiveness at an urban scale; developing more robust models of building risk/ resiliency and aggregate inventories of community risk/ resiliency for use in mitigation, land use planning, and emergency planning; enhancing efforts to upgrade the immense inventory of existing structures and lifelines to be more earthquake-resilient; developing a broader understanding of resiliency-based performance objectives for building and lifeline design and construction; building the next generation of post-disaster damage assessment tools and emergency response and recovery “dashboards” based upon sensing networks; and sustaining systematic monitoring of post-disaster response and recovery activities for extended periods of time.
Envisioning Resilient Communities, Now and in the Future
The National Earthquake Hazards Reduction Program (NEHRP) envisions: A nation that is earthquake-resilient in public safety, economic strength, and national security. The White House National Security Strategy, released in May 2010, offers the following definition of resilience: the ability to prepare for, withstand, and rapidly recover from disruption, and adapt to changing conditions (White House, 2010). The first part of this definition encapsulates the vast majority of work that has been done under NEHRP and as part of modern earthquake engineering research and practice: strengthening the built environment to withstand earthquakes with life-safety standards and codes for new buildings and lifeline construction, developing methods and standards for retrofitting existing construction, and preparing government institutions for disaster response. The second half of this definition captures much of the recent learning and research in earthquake engineering: codes and standards that consider post-disaster performance with minimal to no disruption, as well as the linkages between building and lifeline performance and business, macro-economic, societal, and institutional recovery. But, there is much more work yet to be done, particularly in translating research into practice.
What the 1994 Northridge, 1995 Kobe, and 2010 Chile earthquake and the 2005 Hurricane Katrina disasters have in common is that they all struck relatively dense, modern urban settings, and collectively illustrate varying degrees of resilience in modern societies. Resilient communities need more than physical resilience, which is best characterized by the physical condition of communities’ buildings, infrastructure, and hazard defenses. They need to have environmental, economic, social, and institutional resilience as well. They also need to do more than withstand disruption; resilient communities need to be able to rapidly recover and adapt to the new conditions created by a disaster.
We are now familiar with the physical vulnerabilities of New Orleans’ levee system, but Hurricane Katrina struck a city that lacked resilience across these other dimensions as well; conditions that likely influenced New Orleans’ lack of adaptive capacity and slow recovery in the five years following the disaster (Public Strategies Group, 2011). Prior to Hurricane Katrina, New Orleans’ population (455,000 people in 2005) had been in decline for 40 years, resulting in 40,000 vacant lots or abandoned residences, a stagnant economy, and local budgetary challenges that severely affected the maintenance of local services, facilities, and infrastructure, most notably the school, water, and sewer systems (Olshansky and Johnson, 2010). In addition, New Orleans’ social fabric was also very fragile. In 2005, the city’s median household income of $27,000 was well below the national average of $41,000, as were the home-ownership and minimum literacy rates of 46 and 56 percent, respectively (compared with the national averages of 68 and 75 percent, respectively) (U.S. Census Bureau, 2000; U.S. Department of Education, 2003). The city’s poverty rate of 23.2 percent was also much higher than the national rate of 12.7 percent, and 29 percent of residents didn’t own cars (U.S. Census Bureau, 2004).