This article originally appeared in the May/June 2019 issue of Geostrata, the official bi-monthly magazine of the Geo-Institute of ASCE.
America’s aging and deteriorating infrastructure is being overstressed by more frequent and extreme weather events involving heavy precipitation, coastal flooding, snow, ice, extreme heat, and wildfires, and longer-term climate trends including changing average precipitation and temperature. Without infrastructure adaptation, changes in climate and the increasing frequency, severity, and intensity of extreme weather events will continue to overwhelm infrastructure performance.
To protect our economy, national security, essential services, communities, and personal well-being, we cannot continue to design for historical conditions. If we can adapt our infrastructure design, construction, and management processes to withstand future hazards, we can build system resilience, thus increasing our ability to withstand and bounce back from extreme events.
The Business Case for Adaptation
In 2018, the United States experienced 13 weather and climate disasters that each exceeded $1 billion in damages. The previous year brought record damages from disasters, recording 16 such events and associated damages over $300 billion. The 2017 Hurricanes Harvey, Irma, Jose, and Maria alone cost the U.S. $200 billion — almost three times more than the 10 hurricanes in 2012 combined, which included Hurricane Sandy, one of the costliest natural disasters in U.S. history.
A recent report by the U.S. Global Change Research Program warns that the American economy could lose hundreds of billions up to 10 percent of its gross domestic product (almost $2 trillion) by the end of this century due to climate change. Moreover, per the current National Climate Assessment, events due to climate change and extreme weather are expected to increasingly disrupt critical services, resulting in power outages, fuel shortages, and travel impediments that will impact multiple interconnected sectors and prevent rapid response and recovery.
While new infrastructure can be designed to resist predicted future conditions, adaptation of existing — often aged and vulnerable — infrastructure should also be part of a comprehensive resilience strategy.
Disaster-management experts estimate that globally, every dollar spent on disaster preparedness and resilience planning has a four- to six-times return in savings for response and recovery. When risk-based geotechnical asset management of transportation systems incorporates adaptation, studies have shown a 60-80 percent life-cycle cost saving in railroad and motorway embankments.
As we face new challenges imposed by climate change and extreme events — to design sustainable new infrastructure and preserve existing ones — there’s a need for a fresh, risk-based mindset.
Extreme weather events can also influence the frequency, severity, and intensity of geohazards. For example, rising temperatures and melting permafrost can lead to loss of bearing capacity and structural damage due to differential settlements; droughts can cause lowering of groundwater, surface subsidence and cracking of structures. Longer drought periods can increase the frequency of wildfires, destroying stabilizing vegetation and increasing runoff and potential for debris flows.
Higher-intensity precipitation can exacerbate burn areas and lead to a higher risk of erosion, mudslides, landslides or rock falls. Factors affecting the severity of these major stressors to communities and the built environment include not only the proximity to the hazard itself (e.g., distance from coasts, mountains, valleys, active faults) and condition of the infrastructure assets or systems, but also the pre-event resilience and response planning.
Physical damage to infrastructure due to climate effects is accompanied by economic damage, increased potential for loss of life, and other impacts to the overall well-being of communities. Landslides in the U.S. alone are estimated to cost $2-$4 billion and cause 20 to 50 deaths annually.
Departments of transportation (DOTs) are proactively taking measures to face extreme events. In Oregon—where landslides are a common chronic problem that may be exacerbated by extreme events, such as during times of heavy precipitation or during earthquakes—the state DOT is developing and implementing more rigorous design standards, retrofitting prioritization plans, and making strategic partnerships to improve rapid response and recovery. For critical lifelines and corridors, hardening and triage plans are predicted to save 5,000 lives during a large seismic event and ensure prompt return to business as usual, illustrating the importance of preparing for extreme events.
Ensuring Future Readiness
In building resilience, lessons from past events should be applied to ensure a better, more sustainable, future, keeping in mind some key aspects:
- Remember that resilience is also about the people we serve. Engage with partners early on. Communicate and work with the public and decision-makers to increase their awareness of risks and resilience initiatives. Consider nonstructural measures to reduce potential consequences and response effectiveness, including hazard-warning systems and signs, pre-planned evacuation routes, emergency action thresholds such as slide movement that triggers road closure, and use of real-time, web-based interactive maps.
- Develop future-focused processes. Use a life-cycle approach to reduce future risks. This requires taking action early, preferably during planning, and considering changes in hazard exposures (e.g., wind or storm intensity, wave impacts, temperatures, precipitation and freeze/thaw cycles) that may modify pavement subgrade support, hydraulic loading, accessibility, and utility of emergency sign and lighting structures, etc. Challenge yourself to think, plan and design beyond a single asset, building or city. Consider system and regional approaches, vulnerabilities and impacts, too.
- Support decision-making and prioritization with quality data and management. Resources are often limited, so agencies and industries can benefit from cooperative partnerships to collect and manage data, also enhancing the understanding of geohazards and associated risks.
- Leverage technology and innovation. Available nature-based solutions (e.g., ecosystem-based approaches such as mangroves along coastlines to moderate wind and wave impacts, green infrastructure, etc.) are typically less invasive to the environment and cost less than geostructural interventions. Emerging technologies, including remote sensing, instrumentation, LiDAR and unmanned aerial systems, can be employed to assess the condition of geotechnical works and guide risk-reduction decisions.
- Take small steps to learn ways to improve designs and reduce risk. Join an ASCE and/or G-I technical committee or attend webinars and conferences that offer sharing of ideas and industry insights on ways to integrate resilience strategies into standard practices.
Geoprofessionals can also leverage new tools, guidance, and lessons learned from recent industry developments in various aspects of asset management and asset life stages, such as:
- RELi — The first resilience rating system and rising leadership benchmark for buildings and neighborhoods, owned and developed by the U.S. Green Building Council in collaboration with the Institute for Market Transformation since 2017.
- Performance Excellence in Electricity Renewal (PEER) — The first global certification program that measures power system and electricity infrastructure performance, while also offering solutions to improve the sustainability, reliability, and resilience of these systems.
- Resilience Innovations Summit and Exchange (RISE) — The first annual nationwide transportation resilience summit with executive tracks for sharing emerging and state-of-the-practice information about how to include resilience across all disciplines: maintenance, operations, asset management, design, construction, and community involvement. RISE is cosponsored by the American Association of State Transportation and Highway Officials, the Transportation Research Board, the Federal Highway Administration (FHWA), the Transportation Security Administration, and the Colorado DOT.
- Geotechnical asset management guidance — The National Cooperative Highway Research Program guidance supports transportation agencies in the implementation of risk-based practices and management concepts for geotechnical assets, applicable to any stage of the asset’s life cycle.
- Geohazards, Climate Conditions, and Extreme Weather Events Manual and Training —To be released by FHWA this year to help agencies develop and implement geohazard programs for quantifying and reducing risk in a cost-efficient manner. Guidance principles will be provided for system-wide vulnerability assessment, adaptation analysis for individual assets, and risk-based management system development. Continual improvement is emphasized through performance evaluations and communication with the public.
As we face new challenges imposed by climate change and extreme events — to design sustainable new infrastructure and preserve existing ones — there’s a need for a fresh, risk-based mindset. Forward-looking design philosophy, operations, planning, and standards can reduce exposure and vulnerability, while providing additional benefits, such as reductions in greenhouse gas emissions.
It’s our responsibility as infrastructure professionals to build resilience in the communities we serve by planning and designing new and existing infrastructure for future conditions and multiple types of natural and man-made hazards.
Read the article on the Geostrata web page.