Coastal cities in the Southeast and Gulf regions of the United States are becoming increasingly more vulnerable to tropical cyclone-driven hazards and sea level rise due to increased urbanization and a changing climate. National standards, such as ASCE 7, are inadequate for enhancing community resilience to these hazards because these standards apply to the design and performance assessment of individual buildings and other facilities. In contrast, winds and storm surges from tropical cyclones and sea level rise are spatially non-homogeneous and place non-uniform uncertain demands on the community as a whole. This study introduces a new framework for systematically identifying scenario tropical cyclone events that correctly represent the differing spatial and temporal scales of the associated hazards and are suitable for risk-informed resilience assessment of coastal communities. Scenario events that are dominant contributors to risk, coupled with fragility models of engineered facilities and loss estimation models, are used to identify infrastructure damage patterns within the community and form an improved basis for long-term risk-informed resilience planning. A community patterned after Mobile, AL is used to demonstrate this framework and to appraise its extensibility to other coastal communities.

The growth of structural reliability theory and applications, along with a recognition of its role in guiding the structural engineering profession in addressing some of the most important issues in design of the built environment, represents one of the key engineering achievements during the past five decades. Structural reliability provides a unifying framework for managing uncertainties affecting performance of structures and a quantitative link between the practice of structural engineering and its social consequences. Such links perhaps are most obvious in probability-based codified design and performance evaluation but there are numerous other applications, which are summarized in this special issue. As the field has matured, researchers in reliability have worked with structural engineers to elevate both the practice of structural engineering and the quality of research to levels that otherwise would not have been possible. The Joint Committee on Structural Safety has played a central role in this historic development and it will inspire future opportunities for the reliability community to build upon past successes to improve structural engineering and construction practices. This paper surveys the key theoretical developments and milestones that enable these opportunities.

This paper investigates the far-reaching effects of climate change on coastal communities, focusing on sea-level rise (SLR) and its impact on housing stability and employment across diverse sectors and geographical areas. We examine the repercussions of varying SLR scenarios on the population and employment associated with various economic sectors in the Northern Gulf of Mexico (Gulf), a topic on which there are notable gaps in the literature. Our analysis predicts that 2.3% of current employees will become vulnerable by 2100 to SLR alone, increasing to 4% when coupled with a category 1 hurricane and 18% with a category 5 hurricane, assuming no adaptation measures. If urbanization, employment growth, and housing choices-driven by proximity to workplaces-remain unchanged, these percentages will be 8, 11, and 34% for projected employees. Industries such as construction, health care, and accommodation and food services are particularly at risk due to SLR alone along the Northern Gulf Coast. The threat extends to other sectors like retail trade, transportation, and education across Texas, Louisiana, Mississippi, and Florida, especially under category 5 hurricanes. Many employees in these sectors currently reside near shorelines, suggesting significant workforce relocation will be required. Vulnerability to economic losses will rise among individuals aged 30 to 54, with nearly half of at-risk projected employees belonging to higher earning groups. While these individuals may have resources to manage relocation, remaining elements of the population are socially vulnerable due to limited financial means and alternatives, highlighting the need for targeted support and equitable risk mitigation.

Tropical cyclones pose significant threats to the resilience of coastal communities, underscoring the need for reliable wind field models to support robust hazard analyses. Parametric wind models (PWMs), despite their computational efficiency, often fall short in capturing intricate wind-terrain interactions, leading to inaccurate resilience evaluations for spatially-distributed civil infrastructure systems situated in complex terrains. This study introduces an innovative approach that integrates the strengths of numerical wind models to handle intricate terrain features into PWMs through a deep learning-based Convolutional Neural Network for Terrain Modification (CNN-TM). The CNN-TM model, trained over 3 million km(2) of numerically simulated high-resolution wind fields, enhances terrain representation in PWMs by generating 450 m-resolution terrain-modified wind fields for both wind speed and direction. The accuracy and efficiency of this integration are validated across multiple scales: grid (similar to 0.2 km(2)), patch (similar to 506 km(2)), and region (similar to 34,000 km(2)). Applications during Typhoon Hagupit (2020) in Zhejiang Province, China, demonstrate its practical effectiveness across a 105,000 km(2) area. By leveraging deep learning to synergize numerical and parametric models, the CNN-TM model addresses limitations of traditional PWMs and provides a robust tool for resilience-oriented decision-making for infrastructure systems in coastal regions characterized by complex terrains.

To date our built environment is broadly developed and maintained on the basis of structural design standards. Most design standards contain simplified semi-probabilistic safety concepts that help daily structural engineering decision making using simple calculus. In this paper research about the rational basis for the calibration of these simplified code formats is reviewed and the potential for further developments is presented.

Tornadoes are intense localized convective windstorms that are among the most devastating natural hazards that occur in the United States. Although the probability of any tornado striking one particular building in any given year is quite low because of its small footprint, when strong tornadoes strike densely populated areas, the results can be catastrophic; the Joplin, MO tornado of 2011 caused 161 fatalities and nearly $3 billion in damages. Such losses are projected to increase in the future as a result of urbanization and economic development. ASCE Standard 7-22 on Minimum Design Loads has, for the first time, included new reliability-based design criteria for tornado loads. The objective of this paper is to provide archival documentation of the basis for these tornado-resistant load provisions in Chapter 32 of ASCE 7-22. This paper summarizes the significant challenges that were overcome in addressing the fundamental differences between effects of tornado and nontornadic winds and the higher uncertainties associated with tornado wind pressures that must be accommodated in the risk-informed framework of ASCE 7-22. These challenges were addressed through reliability analyses that led to new tornado load criteria that provide reasonable consistency with the reliability delivered by existing criteria for nontornadic winds.

Standards for the design of bridges, buildings and other infrastructure specify design loads for climatic hazards such as temperature, snow, wind, and floods based on return periods presented in maps or tables that account for regional differences. These design loads were developed from statistical analyses of historical hazard data under the assumption that the past is representative of the future. Climate change may affect the frequencies and intensities of environmental hazards which, depending on regional variations, raises questions as to whether structures designed to current specifications will meet minimum safety standards over their future service lives. This paper critically appraises issues related to using historical hazard data for future designs. It reviews basic principles of uniform reliability, that modern design codes use as the basis for ensuring minimum levels of safety, describing the relationship between hazard return periods, structural reliability, risk and the maximum loads expected within a structure's service life. Simple examples involving wind effects on structures demonstrate how to calibrate structural design hazard maps for climate-related extreme events to meet the minimum standards of safety implied in current specifications. The paper also introduces a possible practical approach to account for climate change when designing new structures and assessing the safety of existing facilities.

Approximately 11% of the world's population lives within 10 km of an ocean coastline, a percentage that is likely to increase during the remainder of the 21st century due to urbanization and economic development. In the presence of climate change, coastal communities will be threatened by increasing damages due to sea-level rise (SLR), accompanied by hurricanes, storm surges and coastal inundation, shoreline erosion, and seawater intrusion into the soil. While the past decade has seen numerous proposals for coastal protection using adaptation methods to deal with the deep uncertainties associated with a changing climate, our review of the potential impact of SLR on the resilience of coastal communities reveals that these adaptation methods have not been informed by community resilience or recovery goals. Moreover, since SLR is likely to continue over the next century, periodic changes to these community goals may be necessary for public planning and risk mitigation. Finally, community policy development must be based on a quantitative risk-informed life-cycle basis to develop public support for the substantial public investments required. We propose potential research directions to identify effective adaptation methods based on the gaps identified in our review, culminating in a decision framework that is informed by community resilience goals and metrics and risk analysis over community infrastructure life cycles.

Social institutions such as hospitals and schools are among the main pillars of community stability. A drop in the functionality of hospitals and schools is likely to have short-term and long-term effects on a community, including a reduction in medical interventions, an increase in unschooled children, and population outmigration in search of essential social services. However, comprehensive community resilience models that consider the role played by social institutions in community stability following natural disasters are scarce at the present time. This paper provides a literature review and critical appraisal of previous studies on the resilience of hospital and school systems and their impact on community well-being. The review encompasses existing resilience models for single hospitals and schools, their role when connected with other hospitals and schools in a network, their reliance on each other as interdependent systems, and their role in community resilience and stability. Different mitigation strategies and policies to enhance hospital and school systems’ resilience after extreme natural hazards are also summarized. The paper concludes with a series of recommendations to improve current models for social institutions, enhance the connection between existing hospital and school resilience models and community resilience frameworks, and develop social stability indices that policymakers can use in preparing and mitigating future extreme events.

A risk-informed decision-making approach is required that accounts for the positive spatio-temporal stochastic dependencies in demand and response on systems to assess their risks of failure and to identify cost-effective strategies to manage risk and enhance resilience. In this chapter, major attributes that make a community resilient are de-aggregated to the building level to facilitate development of systems that optimize building performance with respect to resilience and sustainability goals. The research hypothesis is that it is possible to develop risk-informed performance criteria for individual resilient and sustainable buildings exposed to a spectrum of natural hazards, which can be matched to community goals; that building attributes can be identified and parameterized to support this general risk-informed decision framework; and that the risk-informed decision framework supporting these performance criteria for individual buildings will enable enhanced community resilience and sustainability by targeting public and private investments to manage life-cycle costs.

Coastal civil infrastructure is vulnerable to the effects of climate change. Hurricane storm surge and coastal flooding can cause significant hydrostatic and hydrodynamic loads on structures while saltwater intrusion (SWI) may lead to deterioration of foundations. The effects of saltwater intrusion due to Sea Level Rise (SLR) on the foundations of buildings and other civil infrastructure is poorly understood. Such damages may not be detected in a timely fashion nor be insured, leading to significant and unanticipated expenses for building owners. In this study, we evaluate the impact of SWI due to various SLR scenarios on the corrosion of reinforcement in foundations of nearly 137,000 residential buildings in low-lying areas surrounding Mobile Bay, AL. We find that the potential for costly damage is significant. Under an extreme SLR scenario, the annual expected repair costs for the foundations of the studied homes may reach as much as US$90 million by 2100.

Standards for design of bridges and buildings specify design load intensities for climatic hazards such as temperature, snow, wind, and floods based on return periods presented in maps or tables that account for pertinent regional differences. These maps and tables were developed from statistical analyses of historical data under the assumption that the past is representative of the future. Yet, there is evidence that climate change is affecting the frequencies and intensities of environmental hazards which, depending on regional variations, raises questions as to whether buildings and bridges designed to current specifications will meet minimum safety standards over their projected future service lives. This paper critically appraises issues related to using historic hazard data for future structural designs in view of climate change. First, the paper reviews the basic principles of uniform risk that most modern structural codes use as the basis for ensuring a minimum level of safety. The paper describes the relationship between risk, structural reliability, hazard return periods and the maximum loads expected within a structure's service life. A simple example demonstrates how structural designs based on existing hazard maps may not necessarily meet the minimum standards of safety implied in current specifications. The paper also introduces a possible practical approach to account for climate change in the design of new structures and the safety assessment of existing facilities.