In This Issue
Summer Bridge Issue on Engineering for Disaster Resilience
July 1, 2019 Volume 49 Issue 2
The articles in this issue present examples of engineering innovation to develop resilient infrastructure.

Editor's Note: The Rapidly Growing Need for Resilient Infrastructure

Monday, July 1, 2019

Author: Thomas D. O’Rourke

Planet Earth is both highly populated and increasingly unsettled with respect to natural hazards. Population expansion exposes large numbers of people and expanses of infrastructure to extreme events such as earthquakes, tsunamis, hurricanes, floods, and wildfires. These and other disasters can disrupt the social fabric and economic balance of an entire region, and even cascade into worldwide supply chain disruptions, insurance losses, and financial instability.

Within the past 15 years the world has witnessed the 2004 Sumatra-Andaman and 2011 To–hoku  earthquakes and tsunamis, the 2010 earthquake off the coast of Chile, and the 2010–11 Canterbury (NZ) earthquake sequence. Three of these earthquakes are among the largest six ever recorded. In the United States, Hurricanes Katrina (2005), Sandy (2012), Harvey (2017), Maria (2017), and Irma (2017) are the country’s five most expensive hurricanes—three of them in the same year.

Instead of being rare events, megadisasters from -natural hazards will be experienced with much greater frequency. The severity and far-ranging consequences of these events are establishing a new normal for natural disasters—and a corresponding challenge to the engineering profession to help develop the resilient infrastructure needed to reduce their impact.

Resilience can be defined as the ability of a community to withstand and recover rapidly from disruptions and to adapt to changing conditions (White House 2011). Infrastructure provides the resources and services that sustain communities. It includes public and private sector buildings, transportation facilities, energy generation and delivery systems, water supplies, telecommunications, and waste conveyance and treatment networks.

Resilient infrastructure, however, involves much more than the protection and emergency operation of core facilities. It involves complex interactions among the government agencies and utilities that operate it, the companies and businesses that design and build it, the institutions that finance and fund it, and the people who depend on the infrastructure (NIST 2016).

A prevailing theme among the articles in this issue is the social dimension of infrastructure and the corresponding need to approach resilience as both a social and technical problem. Infrastructure policy and -progress must address the combined social and technical dimensions of infrastructure, including inter-dependencies among the physical, social, and economic systems that communities depend on.

An extra dividend from investment in resilient infrastructure is improved performance on a day-by-day basis. These investment returns are quite significant in the long term when improvements in safety and efficiency are integrated over many years. Daily improvements add to the value gained from the primary goal of avoiding infrastructure disruption and its economic impacts, which are substantial under extreme conditions.

Innovation to Enhance Resilience

If necessity is the mother of invention, then—in a world with an expanding population and simultaneous exposure to the effects of climate change—reducing the impact of natural hazards should necessitate innovation. Natural hazards have in fact been major agents of change in approaches to infrastructure, acting as a catalyst for improving performance under extreme conditions and for planning and engineering that improve daily operations.

The articles in this issue present examples of engineering innovation to develop resilient infrastructure. The innovations involve new ways of formulating and managing risk, of planning and constructing for multiple hazards, and of engaging communities and public/private agencies. Some of the most creative work on infrastructure involves engineering to reduce earthquake and hurricane risk.

One of the great challenges of developing infrastructure is the dual character of the task: Infrastructure is both local—embedded in the local population, inventory of buildings and facilities, business structure, and politics—and subject to universal principles of engineering and social behavior. The general principles of infrastructure must be addressed contemporaneously with the particular characteristics of local communities. Moreover, there is never only one approach, and local solutions are subject to change over time.

Resilient infrastructure provides valuable insight on how to deal with this dual character. The urgency of addressing hazards, especially in vulnerable communities, helps to promote common purpose and gain public support. At the same time, lessons learned in Los Angeles and San Francisco for infrastructure resilient to earthquakes and in New York City and Houston for infrastructure resilient to hurricanes have relevance for communities at risk everywhere: Experience gained from addressing one type of hazard has value for communities subject to other types of hazard. Organiza-tional and financial innovations to reduce the risk of natural hazards provide clues for advancing infrastructure more generally.

In This Issue

The opening op-ed by New York’s Governor Andrew Cuomo describes the rehabilitation of the Canarsie Tunnel, an example of infrastructure innovation following Hurricane Sandy. The tunnel is a critical link in a New York City subway line that carries 250,000 daily commuters, and its rehabilitation was required to repair structural and electric power components damaged by Hurricane Sandy. The project, which started nearly seven years after the hurricane, illustrates the long tail of the recovery curve for core infrastructure after a natural disaster. It also shows the importance of community-oriented objectives in the implementation of resilient infrastructure. In this instance, community objectives were met by breaking the rules of conventional tunnel rehabilitation and overturning traditional agency approaches by enlisting an external academic expert team empaneled by the governor to review the project plans.

Next, Bilal Ayyub and Alice Hill address climate change and its effects on resilient infrastructure design. They discuss approaches for dealing with uncertainty and show how the engineering community is responding to climate change with risk-based adaptive design procedures. They provide guiding criteria, questions, and examples, and review policy options for building resilient infrastructure.

Charlie Scawthorn and Keith Porter provide further treatment of risk-based engineering with a discussion of performance-based design (PBD) and its adaptation to multiple hazards. They report on the benefits of improved building codes for resilient infrastructure, and illustrate with an example of benefits from resilient water distribution grids to reduce fire risk in cities vulnerable to earthquakes. They consider technological, institutional, and regulatory issues that need to be addressed for an effective multihazard approach.

Greg Baecher, Michelle Bensi, Allison Reilly, Brian Phillips, Ed Link, Sandra Knight, and Gerry Galloway explore the paradigm shift from standards-based engineering approaches to risk-informed project plans for resilient infrastructure. They focus on the impact of hurricanes and floods on the evolution of infrastructure design, and consider the implications of a shift from 20th to 21st century hazard-resilient practices for the education of the next generation of engineers.

In the next article, Chris Rojahn, Laurie Johnson, Veronica Cedillos, Terri McAllister, Steve McCabe, and I discuss societal needs and the interdependencies of six critical infrastructure systems: electric power, gas and liquid fuel, water, wastewater, telecommunications, and transportation networks. Based on an assessment of lifeline infrastructure performance commissioned by the National Institute of Standards and Technology (NIST), suggestions are provided for policy, modeling, and research, as well as infrastructure performance -levels and timeframes for recovery of critical services and resources.

Bruce Ellingwood, John van de Lindt, and Terri McAllister address the development of resilient communities and describe the work of the NIST-supported Center for Risk-Based Community Resilience. The efforts of this multiuniversity consortium go beyond improvements in physical assets and emergency response to consider the social needs of communities, including postdisaster recovery.

Lucy Jones and Marissa Aho explain how the City of Los Angeles has addressed natural hazard risk by implementing a long-term plan, Resilience by Design, to improve seismic resilience through city council ordinances, executive action, and partnership activities. They discuss how science and policy are integrated in the city plan, and draw useful lessons from the Los Angeles experience for other scientists, engineers, urban planners, and communities that want to connect scientific research to policies for resilient communities.

Craig Davis and John Shamma describe a historic collaboration of the Los Angeles Department of Water and Power, Metropolitan Water District, and -California Department of Water Resources to develop and apply measures for a seismic-resilient water supply for the 19 million residents of the Los -Angeles–San Diego region. They focus on projects to ensure flowing water in the event of a significant rupture of the San Andreas Fault and a collaborative plan for system-wide risk reduction. The formation of this regional task force required overcoming institutional constraints and differences in organizational culture to achieve unity of purpose and commitment to widespread improvements.

The Way Ahead

A critical overarching factor in these articles is the institutional culture of the agencies and organizations responsible for planning, constructing, and maintaining infrastructure. That culture is at the heart of future changes in the way engineers do business. Necessary changes in approach start with the recognition that there is an important difference between change agents and agencies that don’t change.

As engineers, we need to ask ourselves if we want to be participants in agencies that change versus those that do not. For infrastructure this is an existential question. The infrastructure challenges facing the nation are so large that progress will be achieved only through -changes in the culture of operating and regulatory agencies, reductions in institutional restrictions, and innovations in financing and funding to create resilient and sustainable systems.

The development of resilient infrastructure provides many lessons and fresh thinking about the changes needed to accommodate extreme demands amid complex technical and social conditions. I hope this issue will stimulate fresh thinking about infrastructure and be a change agent for much-needed improvements.


Thanks are extended to the Office of Los Angeles -Mayor Eric Garcetti, National Institute of Standards and Technology, National Science Foundation, Los Angeles Department of Water and Power, Metropolitan Water District, and California Department of Water Resources for the institutional, information, and research support of the work described in this issue.

We appreciate the efforts of the following experts enlisted to ensure the articles’ coverage, accuracy, and evidence base: John Boland, James Harris, Kenneth Hudnut, Eric Letvin, David Myerson, Chris Poland, and Jonathan Stewart.

As managing editor of The Bridge, Cameron Fletcher provided thoughtful insights and recommendations for improvements. She is a pleasure to work with.


NIST [National Institute of Standards and Technology]. 2016. Critical Assessment of Lifeline System Performance: Understanding Societal Needs in Disaster Recovery. NIST GCR 16-917-39 Report, prepared by the Applied Technology Council for NIST. Gaithersburg MD.

White House. 2011. Presidential Policy Directive/PPD-8: National Preparedness. Washington.

About the Author:Thomas D. O’Rourke (NAE) is the Thomas R. Briggs Professor of Engineering in the School of Civil and Environmental Engineering at Cornell University.