March 2021 marked the 10th anniversary of the Great East Japan (Tohoku) Earthquake. On the afternoon of 11 March 2011, a magnitude 9.1 megathrust earthquake struck where the Pacific Plate subducts underneath the Honshu region of Japan. This was a massive event. The earthquake rupture lasted 150-160 seconds, with shaking in many communities felt for five or more minutes. The energy released by the earthquake could power the city of Los Angeles for more than a year. Japan was shifted 8 feet to the east and the earth’s axis shifted about 6.5 inches. The subsequent tsunami reached more than 10 meters in many places, devastating large portions of Japan’s eastern coast. The resulting destruction is estimated to have caused tens of billions of dollars in damage, destroyed tens of thousands of buildings, and caused the deaths of nearly 20,000 people.
Japan has a long history of regularly occurring major earthquakes and averages more than 100 magnitude 5 or larger earthquakes annually. Recognizing this hazard, the Japanese government has invested heavily in mitigation. Japan has some of the world’s most rigorous earthquake engineering standards and building codes. Immediately after the 2011 earthquake, Japan’s national government centralized its recovery efforts and adopted a broad strategy of rebuilding stronger, truly focusing on resilience. Rather than investing in a single large mitigation solution (e.g., taller seawalls), they pursued multi-layered protection strategies including natural barrier enhancement, elevated roadways between the sea and their communities, and natural area restoration.
Additionally, affordable housing and community economic development plans provided a rebalancing to address equitability. Using state-of-the-art risk modeling solutions as the basis for this approach, government officials are also better able to communicate risk to their citizens. Those efforts continue to this day, with regular hazard assessments and ongoing investments in mitigation embedded in public and private economic development. Japan has listened to its history, regularly examines its possible future, invested in its cities and infrastructure, instilled a culture of preparedness in its residents, and learned from the past as it looks to the future. The United States should do the same.
Partial Mitigation Is Not Enough
The United States has experienced an unprecedented number of major disasters in its recent past, and every indication is that this trend will continue. A few well-known examples demonstrate the slow evolution of resilience-focused disaster recovery.
Hurricane Katrina (2005) was one of the strongest hurricanes ever recorded in the Gulf of Mexico. The destruction it wrought across southern Mississippi and Louisiana resulted in devastated communities and caused several hundred billion dollars in damage. In the aftermath, Congress approved billions in recovery efforts, but it is widely accepted that not enough mitigation has been undertaken.
The Mississippi River Delta is an incredibly complex natural region. The main focus in post-Katrina rebuilding has been storm surge, as rising sea levels, stronger hurricanes, and eroding natural barriers are amplifying the risk annually. The levee system built after Katrina, while stronger than the previous barrier, may not be tall enough; at best, it is only a part of the solution. For example, New Orleans relies on an antiquated storm water pumping system that will cost more than $1 billion to replace, and it is not needed solely for major hurricanes. Heavy rain events quickly overwhelm the system, resulting in flooding across the city. Natural ecosystems, which protect communities, require considerable investment in protection and restoration. And additional investment is needed to address existing economic and social inequalities that disasters quickly exacerbate. More aggressive and holistic mitigation is needed.
In 2012, Superstorm Sandy resulted in the most devastating natural disaster in several northeastern states’ histories. In this instance, recovery efforts were more holistic, albeit still underfunded. The impacted states received tens of billions of dollars in Community Development Block Grant–Disaster Recovery (CDBG-DR) funding to augment their recovery efforts. The flexibility of this program allowed for a broader approach, and saw reconstruction efforts focus on mitigation and long-term resilience. Additionally, projects included consideration of local history, economic development, cultural preservation, social equity, and climate change. However, years of high-risk community development, and a lack of investment in hardening infrastructure, means that much more funding is still needed to reduce future impacts.
Texas has a well-established risk from tropical systems. Major hurricanes such as Harvey (2017), Rita (2008), and Ike (2005) brought damaging storm surge, widespread flooding, and impactful winds. Hurricane Harvey shattered records by dumping more than 60 inches of rain in parts of Harris County and major flooding across large swaths of the state, causing more than $125 billion in damages. Although tens of billions of dollars have been provided for recovery, the list of flood mitigation projects that have been identified far exceed available funds.
No End in Sight
Annually over the past decade, the United States has witnessed at least a half a dozen billion-dollar disasters, culminating in 2020, when more than 20 billion-dollar disasters occurred (see Fig. 1). Both the types of disasters, as well as their locations, have been broadly distributed. Severe storms have repeatedly struck the central and southern United States. Hurricanes have pounded the Gulf Coast and Atlantic seaboard. Wildfires have destroyed entire communities in California and the Pacific Northwest. All of this is in addition to the many hundreds of localized floods, tornadoes, ice storms, and other natural hazards that occur every year. Constant exposure to billion-dollar disasters can cause disaster fatigue, which has been exacerbated by the mental, physical, and economic challenges caused by the COVID-19 pandemic. As such, support for expensive resilience-focused recovery investments can wane due to competition with other priorities.
Compounding this issue is that many mitigation projects are not obvious, thus the community does not directly experience the investments made. For example, Dr. Lucy Jones, one of the world’s leading seismologists, recently noted that one of the greatest risks to the Los Angeles region is the vulnerability of its water system to an earthquake. The cost to retrofit the system would be many billions of dollars. And investing such money now would not result in any notable change for residents. After the project, water will still flow from faucets, as it does today. Justifying such an expense, when so many other pressing societal issues remain unfunded, is difficult. However, the assuredness of access to water after an earthquake is far from guaranteed. As was witnessed recently in Texas, when frozen water pipes led to an unprecedented crisis (particularly for lower socioeconomic residents), the primary impacts of a natural hazard are only part of the story. Following a major earthquake, and absent a substantial investment in water system mitigation, the greater Los Angeles region could experience a water crisis for more than a year.
An Opportunity Exists
There is hope on the horizon. Earlier this year, the Biden Administration announced its intention to increase mitigation funding by injecting $10 billion through existing Federal Emergency Management Agency programs. What will help to get large, impactful mitigation projects started may be found in the anticipated infrastructure bill. Not only would both investments begin to undo decades of neglect of America’s infrastructure, but they would also serve to create jobs and build a genuinely more resilient nation.
Regardless of the source or amount of available funding, it is important to ensure that projects are designed and built as accurately and efficiently as possible. There are several examples of mitigation projects that were underbuilt due to funding limitations. Fortunately, emerging technologies are available that can assist decision-makers, engineers, and mitigation specialists to more accurately understand the risks they wish to eliminate or greatly reduce.
The past decade has witnessed the rise of machine learning as a companion to engineering, environmental and geophysical sciences, and traditional physical modeling to allow for faster and more accurate risk modeling. It is also considerably less expensive than traditional methods of assessing potential impacts and the physical improvements that minimize or eliminate them. Additionally, the availability of massive amounts of computational power allows for a nearly unlimited number of scenarios to be assessed and analyzed, with the most cost-effective options to be determined. Armed with faster, better, and cheaper assessment and planning tools, mitigation experts are more empowered to achieve the collective goal of building a resilient future in a much more cost-effective and timely manner.
The United States finds itself at a point from which it can quickly embark on a new journey toward resilience. Repetitive major disasters, and their associated costs, have provided a convincing argument that significant investments in mitigation must be made. Technological advancements provide for faster, smarter, and more effective project identification and design. The Biden administration has laid out initial funding opportunities to fuel the start of this work. These efforts must be strongly supported if the United States is going to maintain its place in the global economy and withstand future disasters.