Extreme weather events the last few years have been testing the nation—s infrastructure – and by extension, the civil engineering community. Record floods, hurricanes, tornados, droughts, wildfires, snow storms, and other natural and man-induced disasters have impacted many areas of the country. A new report from the National Academies, —Disaster Resilience: A National Imperative,— highlights the importance of enhancing our resistance and resilience to such disasters. (Download a copy of the report at www.nap.edu/catalog.php?record_id=13457)
—Without innovations to improve resilience, the cost of disasters will continue to rise both in absolute dollar amounts and in losses to social, cultural, and environmental systems in each community,— said Susan L. Cutter, director of the Hazards and Vulnerability Research Institute at the University of South Carolina and chair of the committee that released the report.
The report recommends that risk-reduction measures combine tangible actions such as building dams and levees and reinforcing critical structures with other efforts such as zoning laws, land-use planning, and communication strategies. In addition, the long-term process of improving resilience will require investment from both the public and private sectors, the report—s authors said.
But that process also will require improved designs. —We need to rethink how we protect infrastructure,— said Joseph Schofer, Ph.D., a professor of civil and environmental engineering at the McCormick School of Engineering and Applied Science at Northwestern University and director of the Infrastructure Technology Institute. Schofer hosts a monthly podcast on issues related to the nation—s infrastructure at http://theinfrastructureshow.com.
—If there is any good news in these repeated assaults, we can view them as experiments – of a type we would never intentionally conduct ourselves – to find the vulnerabilities in our infrastructure, including roads, bridges, transit systems, water supply and recovery systems, homes, and buildings,— Schofer said.
In the latest —experiment,— Hurricane Isaac parked over New Orleans in late August – seven years to the day after Hurricane Katrina – offering the first significant test of the U.S. Army Corps of Engineers— pump, flood wall, and levee improvements. By all news accounts, the more than $14 billion Hurricane and Storm Damage Risk Reduction System (HSDRRS) protected the city of New Orleans as designed.
However, areas of southeast Louisiana outside of the system experienced record flooding, raising questions about whether the HSDRRS unintentionally increased flooding of surrounding areas. U.S. Senator David Vitter requested that the Corps conduct a scientific review of the issue and the Corps agreed to perform additional modeling based on Hurricane Isaac.
—Extensive preconstruction storm surge modeling and analysis was performed in developing the HSDRRS,— the Corps said in a press release. —Surge modeling was completed using best available science and engineering, and subjected to the rigors of Independent External Peer Review. … We expect the results [of additional modeling] to indicate that changes in surge elevation are minimal but will defer further comment until the science and engineering work is completed.—
As civil engineers seek to improve the resistance and resilience of the nation—s infrastructure to disasters, expect a greater role for increasingly complex models that can help evaluate the regional impacts of designs before they receive real-world tests.