Helmrich, A., Gerber, B., Gall., M., Horton, P., El Asmar, M., Sailor, D., Neveu, M., El Kassis, R., Sanboskani, H., Vogel, A., Yu, Y., and White, D. (2025). Developing a long-term risk & resilience management strategy for physical asset and critical infrastructure projects. Frontiers in the Built Environment – Urban Science. DOI: 10.3389/fbuil.2025.1530343.
To account for increasing complexity and uncertainty in environmental, social, and technological systems, organizations that manage risk and vulnerability while maintaining large physical asset or infrastructure projects must identify, inventory, and anticipate trade-offs across multiple drivers of change. This article describes an integrated and inclusive process to develop a capabilities-based planning (CBP) framework to inform decision-making for future investments, centering hazard risk reduction and operational resilience. The proposed CBP framework demonstrates an approach to addressing context-specific complexity and uncertainty in decision-making by assessing short and long-term risk within a defined analytic focus. A case study of application is provided, examining the impacts of climate, resource, population, urbanization, and technology drivers on foreign assets for the U.S. Department of State Bureau of Overseas Buildings Operations in Kolkata, India. The process broadly applies to organizations with projects of physical assets and critical infrastructure, which balance tensions in decision-making across multiple objectives in diverse contexts.
Shamsi, N.* and Helmrich, A. Interdependency classification: A framework for infrastructure resilience. Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/adac89.
Critical Infrastructure Systems (CISs) provide essential services for nation-wide security, economy, and social well-being, and these systems are becoming increasingly interdependent to maintain those services. Recent and diverse disturbances worldwide have highlighted that interdependencies within CISs may increase the potential for cascading failures, amplifying the impacts of both large and small-scale disturbances into events of catastrophic proportions. The methodology involved conducting a literature search through scholarly databases and using a snowball approach to identify 12 relevant papers on infrastructure interdependencies. Thematic analysis was then applied to classify 50 interdependencies, which were synthesized into a unified classification system mapped to a foundational framework. The direct citation network visualization tool, Kumu, illustrated citation patterns and guided the analysis. Identifying and classifying various interdependencies, understanding their relationships, and assessing their role in CISs are crucial steps to prevent, mitigate, or manage unfavorable consequences and enhance system resilience. In this article, we compiled and identified classifications of infrastructure interdependencies and described a unified classification. To support the resilience of CISs in periods of stability and instability, infrastructure managers not only need consistent terminology but a shared understanding of interdependencies to ensure said interdependencies within and across CISs are appropriately accounted for throughout the life cycle of infrastructure, from early planning stages to management – reactive or proactive – for disturbances. These are critical steps toward understanding how CISs operate in concert so infrastructure managers may sense and anticipate potential disruptions, manage the impacts and consequences, and adapt to changing future conditions.
2024
Joines, M.*, Horgan, M., Li, R., Helmrich, A., Dirks, A., Tarr, K., Sparks, R., Hoff, R., Kimball, M., and Chester, M. Cross-boundary Risks of Hinterland Hazards to City Infrastructures. Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/ad5fb4.
Extreme weather-related events are showing how infrastructure disruptions in hinterlands can affect cities. This paper explores the risks to city infrastructure services including transportation, electricity, communication, fuel supply, water distribution, stormwater drainage, and food supply from hinterland hazards of fire, precipitation, post-fire debris flow, smoke, and flooding. There is a large and growing body of research that describes the vulnerabilities of infrastructures to climate hazards, yet this work has not systematically acknowledged the relationships and cross-governance challenges of protecting cities from remote disruptions. An evidence base is developed through a structured literature review that identifies city infrastructure vulnerabilities to hinterland hazards. Findings highlight diverse pathways from the initial hazard to the final impact on an infrastructure, demonstrating that impacts to hinterland infrastructure assets from hazards can cascade to city infrastructure. Beyond the value of describing the impact of hinterland hazards on urban infrastructure, the identified pathways can assist in informing cross-governance mitigation strategies. It may be the case that to protect cities, local governments invest in mitigating hazards in their hinterlands and supply chains.
2023
Helmrich, A., Chester, M., Miller, T., & Allenby, B. (2023). Lock-in: Origination and Significance within Infrastructure Systems. Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/acf7e6.
Infrastructure systems have legacies that continue to define their priorities, goals, flexibility, and ability to make sense of their environments. These legacies may or may not align with future needs, but regardless of alignment, they may restrict viable pathways forward. Infrastructure 'lock-in' has not been sufficiently confronted in infrastructure systems. Lock-in can loosely be interpreted as internal and external pressures that constrain a system, and it encourages self-reinforcing feedback where the system becomes resistant to change. By acknowledging and recognizing that lock-in exists at small and large scales, perpetuated by individuals, organizations, and institutions, infrastructure managers can critically reflect upon biases, assumptions, and decision-making approaches. This article describes six distinct domains of lock-in: technological, social, economic, individual, institutional, and epistemic. Following this description, strategies for unlocking lock-in, broadly and by domain, are explored before being contextualized to infrastructure systems. Ultimately, infrastructure managers must make a decision between a locked in and faltering but familiar system or a changing and responsive but unfamiliar system, where both are, inevitably, accepting higher levels of risk than typically accustomed.
Helmrich, A., Chester, M., and Ryerson, M. (2023). Complexity of Increasing Knowledge Flows: Exploring the Southwest Airlines 2022 Meltdown. Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/ace5ce.
The 2022 Southwest Airlines Scheduling Crisis, resulting in approximately 15 000 flight cancellations, demonstrates the challenges of structuring infrastructure systems and their knowledge-making processes for increasingly disruptive conditions. While the point-to-point configuration was the focus of immediate assessments of the failure, it became rapidly evident that the crew-assignment software was unable to operate effectively due to the scale of disruption. The airline failed to recognize environmental shifts associated with internal and external complexity, leaving operations vulnerable to a known potential risk: computer and telecommunications failures due to an extreme weather event resulting in knowledge systems failures. The cascading failures of the crisis emphasize the necessity to invest in adaptive capacity prior to catastrophic events and provide a lesson to other infrastructure managers pursuing resilience in the face of increasingly uncertain environments.
Helmrich, A., Kuhn, A., Roque, A., Kim, Y., Santibanez, A., Grimm, N., and Chester, M. (2023). Interdependence of Social-Ecological-Technological Systems in Phoenix, AZ: Consequences from an Extreme Precipitation Event. Journal of Infrastructure Preservation and Resilience. DOI: 0.1186/s43065-023-00085-6.
Complex adaptive systems – such as critical infrastructures (CI) – are defined by their vast, multi-level interactions and emergent behaviors, but this elaborate web of interactions often conceals relationships. For instance, CI is often reduced to technological components, ignoring that social and ecological components are also embedded, leading to unintentional consequences from disturbance events. Analysis of CI as social-ecological-technological systems (SETS) can support integrated decision-making and increase infrastructure’s capacity for resilience to climate change. We assess the impacts of an extreme precipitation event in Phoenix, AZ to identify pathways of disruption and feedback loops across SETS as presented in an illustrative causal loop diagram, developed through semi-structured interviews with researchers and practitioners and cross-validated with a literature review. The causal loop diagram consists of 19 components resulting in hundreds of feedback loops and cascading failures, with surface runoff, infiltration, and water bodies as well as power, water, and transportation infrastructures appearing to have critical roles in maintaining system services. We found that pathways of disruptions highlight potential weak spots within the system that could benefit from climate adaptation, and feedback loops may serve as potential tools to divert failure at the root cause. This method of convergence research shows potential as a useful tool to illustrate a broader perspective of urban systems and address the increasing complexity and uncertainty of the Anthropocene.
Chester, M., Miller, T., Munoz-Erickson, T., Helmrich, A., Iwaniec, D., McPhearson, T., Markolf, S., Cook, E., and Grimm, N. (2023). Sensemaking for Entangled Urban Social, Ecological, and Technological Systems in the Anthropocene. npj Urban Sustainability. DODOI: 10.1038/s42949-023-00120-1.
Our urban systems and their underlying sub-systems are designed to deliver only a narrow set of human-centered services, with little or no accounting or understanding of how actions undercut the resilience of social-ecological-technological systems (SETS). Embracing a SETS resilience perspective creates opportunities for novel approaches to adaptation and transformation in complex environments. We: i) frame urban systems through a perspective shift from control to entanglement, ii) position SETS thinking as novel sensemaking to create repertoires of responses commensurate with environmental complexity (i.e., requisite complexity), and iii) describe modes of SETS sensemaking for urban system structures and functions as basic tenets to build requisite complexity. SETS sensemaking is an undertaking to reflexively bring sustained adaptation, anticipatory futures, loose-fit design, and co-governance into organizational decision-making and to help reimagine institutional structures and processes as entangled SETS.
Hoff, R., Helmrich, A., Dirks, A., Kim, Y., Li, R., and Chester, M. (2023). Dynamic Criticality for Infrastructure Prioritization in Complex Environments. Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/acbe15.
As infrastructure confront rapidly changing environments, there is an immediate need to provide the flexibility to pivot resources and how infrastructures are prioritized. Yet infrastructures are often categorized based on static criticality framings. We describe dynamic criticality as the flexibility to reprioritize infrastructure resources during disturbances. We find that the most important prerequisite for dynamic criticality is organizational adaptive capacity characterized by flexible goals, structures, sensemaking, and strategies. Dynamic capabilities are increasingly important in the Anthropocene, where accelerating conditions, uncertainty, and growing complexity are challenging infrastructures. We review sectors that deployed dynamic management approaches amidst changing disturbances: leadership and organizational change, defense, medicine, manufacturing, and disaster response. We use an inductive thematic analysis to identify key themes and competencies and analyze capabilities that describe dynamic criticality. These competencies drive adaptive capacity and open up the flexibility to pivot what is deemed critical, depending on the particulars of the hazard. We map these competencies to infrastructure systems and describe how infrastructure organizations may build adaptive capacity toward flexible priorities.
2022
Li, R., Helmrich, A., and Chester, M. (2022). Parking by the Bay: The Supply and Implications of Parking Infrastructure in the San Francisco Bay Area. Journal of Transport and Land Use. DOI: 10.5198/jtlu.2022.2123.
The San Francisco Bay Area is one of the most progressive
transportation regions in the deployment of high-capacity transit
and the use of policies to encourage active transportation. Yet, there
remains a dearth of knowledge on the abundance and location of
parking infrastructure. The extent and location of parking supply,
including on-street and off-street spaces, are estimated for the nine-
county Bay Area by creating a federated database that joins land use,
transportation, parcel, building, and parking code layers to estimate
the number and characteristics of parking spaces at the census block
scale. This bottom-up parking space inventory results in an estimated
15 million parking spaces in the region: 8.6 million on-street and 6.4
million off-street. Residential parking dominates the share of supply
at 70%, followed by commercial at 9.4%. Space density is greatest in
downtown San Francisco, Oakland, and San Jose—largely attributed to
high-rise structures. On-street parking is dominant in the North Bay,
commanding 78% of total parking in Napa, 75% in Solano, 68% in
Sonoma, and 67% in Marin County. Parking area constitutes 7.9% of
the total incorporated area. Notably, when compared to other southwest
cities (Phoenix Metropolitan Area and Los Angeles County), the Bay
Area parking supply appears better utilized considering spaces per
person, per car, and per job. The density and quantity of parking spaces
in the Bay Area are critical insights toward developing targeted policies
that encourage active mobility and support affordable housing.
Markolf, S., Helmrich, A., Kim, Y., Hoff, R., and Chester, M. (2022). Balancing efficiency and resilience objectives in pursuit of sustainable infrastructure. Current Opinion in Environmental Sustainability. DOI: 10.1016/j.cosust.2022.101181.
Efficiency (i.e. optimized use of resources) and resilience principles (i.e. redundancy, diversity, etc.) are often at odds with one another. Despite being particularly acute within infrastructure systems, this tension appears to be under-explored. However, recent advances in ecological and social sciences provide some novel insights into navigating efficiency–resilience trade-offs. Overall, efficiency and resilience are both vital for a system’s longevity and striking a dynamic balance between the two appears to be crucial. Striking this balance in infrastructure systems can be catalyzed by the treatment of resilience as a public good, as well as incorporating exploratory models and stakeholder coproduction in the design and implementation process. Ultimately, the dynamic balance between efficiency and resilience can play a central role in our infrastructure’s ability to successfully operate in environments that increasingly fluctuate between stable and unstable conditions.
Helmrich, A., and Chester, M. (2022). Navigating Exploitative and Explorative Leadership in Support of Infrastructure Resilience. Frontiers in Sustainable Cities. DOI: 10.3389/frsc.2022.791474.
Leadership is a critical component in approaching infrastructure resilience. Leadership, the formal and informal governance within an organization, drives an infrastructure system's ability to respond to changing circumstances. Due to the instability of the Anthropocene, infrastructure managers (individuals who design, build, maintain, and decommission infrastructure) can no longer rely on assumptions of stationarity, but instead that shifts are occurring at a faster rate than institutions and infrastructure organizations are adapting. Leadership and organizational change literature provide considerable insights into the ability of organizations to navigate uncertainty and complexity, and infrastructure organizations may be able to learn from this knowledge to avoid obsolescence. Therefore, this article asks: what leadership capabilities do infrastructure organizations need to readily respond to stability and instability? An integrative leadership framework is proposed, exploring capabilities of collaboration, perception and exploration toward learning, and flexible informal and formal governance leveraged by leadership. These capabilities are driven by underlying tensions (e.g., climate change, emerging technologies) and managed through enabling leadership, a set of processes for pivoting between stability and instability. The framework is then applied to infrastructure organizations. Lack of market competition may make infrastructure organizations more open to collaboration and, therefore, learning. However, the need to provide specific services may cause risk adversity and an avoidance of failure, restricting flexibility and innovation. It is critical for infrastructure organizations to identify their strengths and weaknesses so they may develop an approach to change at pace with their external environments.
Kim, Y., Carvalhaes, T., Helmrich, A., Markolf, S., Li, R., Ahmad, N., Hoff, R., and Chester, M. (2022). Leveraging SETS Resilience Capabilities for Safe-to-Fail Infrastructure and Climate Change. Current Opinion in Environmental Sustainability. DOI: 10.1016/j.cosust.2022.101153.
As the rehabilitation of infrastructure is outpaced by changes in the profile, frequency, and intensity of extreme weather events, infrastructure’s service disruptions and failures become increasingly likely. Safe-to-fail approaches for infrastructure planning and design improve the capacity of cities to adapt for uncertain climate futures by identifying social, ecological, and technological systems (SETS) capabilities to prepare for potential failure scenarios. In this paper, we argue for transforming infrastructure planning and design to effectively utilize safe-to-fail approaches by navigating the opportunities and trade-offs of SETS resilience capabilities. From a technological vantage point, traditional infrastructure planning approaches account for social and ecological domains as external design conditions rather than embedded system characteristics. Safe-to-fail approaches directly challenge the isolation of the technological domain by necessitating a recognition that SETS domains are interconnected and interdependent in infrastructure systems, as such risks and system capabilities for resilience must be managed cohesively.
2021
Helmrich, A., Ruddell, B., Bessem, K., Chester, M., Chohan, N., Doerry, E., Eppinger, J., Garcia, M., Goodall, J., Lowry, C., and Zahura, F. (2021). Opportunities for Crowdsourcing in Urban Flood Monitoring. Environmental Modelling & Software. DOI: 10.1016/j.envsoft.2021.105124.
Flooding is the most common natural hazard, leading to property damage, injuries, and death. Despite the potential for major consequences, urban flooding remains difficult to forecast, largely due to a lack of data availability at fine spatial scales and associated predictive capabilities. Crowdsourcing of public webcams, social media, and citizen science represent potentially important data sources for obtaining fine-scale hydrological data, but also raise novel challenges related to data reliability and consistency. We provide a review of literature and analysis of existing databases regarding the availability and quality of these unconventional sources that then drives a discussion of their potential to support fine-grained urban flood modelling and prediction. Our review and analysis suggest that crowdsourced data are increasingly available in urban contexts and have considerable potential. Integration of crowdsourced data could help ameliorate quality and completeness issues in any one source. Yet, substantial weaknesses and challenges remain to be addressed.
Helmrich, A., Markolf, S., Li, R., Carvalhaes, T., Kim, Y., Bondank, E., Natarajan, M., Ahmad, N., and Chester, M. (2021). Centralization and Decentralization for Resilient Infrastructure and Complexity. Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/ac0a4f.
The capacities of our infrastructure systems to respond to volatile, uncertain, and increasingly complex environments are increasingly recognized as vital for resilience. Pervasive across infrastructure literature and discourse are the concepts of centralized, decentralized, and distributed systems, and there appears to be growing interest in how these configurations support or hinder adaptive and transformative capacities towards resilience. There does not appear to be a concerted effort to align how these concepts are used, and what different configurations mean for infrastructure systems. This is problematic because how infrastructure are structured and governed directly affects their capabilities to respond to increasing complexity. We review framings of centralization, decentralization, and distributed (referred to collectively as de/centralization) across infrastructure sectors, revealing incommensurate usage leading to polysemous framings. De/centralized networks are often characterized by proximity to resources, capacity of distribution, volume of product, and number of connections. De/centralization of governance within infrastructure sectors is characterized by the number of actors who hold decision-making power. Notably, governance structures are often overlooked in infrastructure de/centralization literature. Next, we describe how de/centralization concepts are applied to emerging resilient infrastructure theory, identifying conditions under which they support resilience principles. While centralized systems are dominant in practice and decentralized systems are promoted in resilience literature, all three configurations—centralized, decentralized, and distributed—were found to align with resilience capacities in various contexts of stability and instability. Going forward, we recommend a multi-dimensional framing of de/centralization through a network-governance perspective where capabilities to shift between stability and instability are paramount and information is a critical mediator.
Markolf, S., Chester, M., Helmrich, A., and Shannon, K. (2021). Re-Imagining Design Storm Criteria for the Challenges of the 21st Century. Cities. DOI: 10.1016/j.cities.2020.102981.
Design storm criteria (i.e., the specific intensity and/or frequency to which infrastructure systems are designed to withstand) are a critical part of resilience efforts within urban and infrastructure systems. However, factors like climate change and increasing complexity within our urban systems call into question the viability of current approaches to and implementation of design storm criteria moving forward. This paper seeks to identify design practices and strategies that are well-suited for the increasingly complex and rapidly changing contexts in which our cities and infrastructure are operating. We posit that the advancement of a multi-scalar perspective on resilience will be increasingly necessary in response to the growing challenges our cities and infrastructure face. At the scale of single components/sub-systems, return periods (or similar criteria) will likely remain a necessary element of the design process. At the scale of the entire system(s), approaches like safe-to-fail, robust decision making, and enhanced sensing and simulation appear well suited for complementing existing approaches by more explicitly considering failure consequences in the design and management processes. Ultimately, this paper seeks to spur continual research and advancement of these topics in order to facilitate the evolution of the design storm process for an increasingly complex and non-stationary world.
Meerow, S., Helmrich, A., Andrade, R., Larson, K. (2021). How do heat and flooding risk drive residential green infrastructure implementation in Phoenix, Arizona? Urban Ecosystems. DOI: 10.1007/s11252-020-01088-x.
Green infrastructure is an increasingly popular strategy to simultaneously address challenges associated with urbanization and global environmental change, including increased flooding and rising temperatures. While many cities aim to expand green infrastructure to deliver ecosystem services, their impacts will be limited without significant uptake on private property. Most studies and programs to date focus on public land, so little is known about what would motivate private residents to implement green infrastructure. This study addresses this gap, combining household survey and spatial data from the Phoenix metropolitan region in Arizona by examining what factors predict green infrastructure implementation, with a particular focus on flooding and heat risks. The results suggest that residents are generally aware of their relative exposure to these hazards, but their risk perceptions do not translate into increased implementation of green infrastructure. Prior experience of flood damage is a predictor of stormwater infrastructure implementation, but experience with heat did not impact planting vegetation to mitigate the effects of extreme temperatures. Instead, the decision to implement green infrastructure is likely constrained by limited capacity based on income and homeownership, which can impede people’s ability to make management decisions on private residential property. More research is needed to unpack the seemingly complex factors that shape residents’ decisions to implement green infrastructure on their property.
2020
Helmrich, A., Markolf, S., Hayes, S., Chester, M., Desha, C., Grimm, N. (2020). Using Biomimicry to Support Resilient Infrastructure. Earth’s Future. DOI: 10.1029/2020EF001653.
Infrastructure must be resilient to both known and unknown disturbances. In the past, resilient infrastructure design efforts have tended to focus on principles of robustness and recovery against projected failures. This framing has developed independently from resilience principles in biological and ecological systems. As such, there are open questions as to whether the approaches of natural systems that lead to adaptation and transformation are relevant to engineered systems. To improve engineered system resilience, infrastructure managers may benefit from considering and applying a set of “Life's Principles”—design principles and patterns drawn from the field of biomimicry. Nature has long withstood disturbances within and beyond previous experience. Infrastructure resilience theory and practice are assessed against Life's Principles identifying alignments, contradictions, contentions, and gaps. Resilient infrastructure theory, which emphasizes a need for flexible and agile infrastructure, aligns well with Life's Principles, addressing each principle and most sub-principles (excluding “breakdown products into benign components” and “do chemistry in water”). Meanwhile, resilient infrastructure practice only occasionally aligns with Life's Principles and contradicts five out of six principles. As resilience theory advances, Life's Principles offer support in broadening how infrastructure managers approach resilience, and by using biomimicry, infrastructure managers can be better equipped to deploy resilience for complexity and uncertainty.
Carvalhaes, T., Markolf, S., Helmrich, A., Kim, Y., Li, R., Natarajan, M., Bondank, E., Ahmad, N., and Chester, M. (2020). COVID-19 as a Harbinger of Transforming Infrastructure Resilience. Frontiers in Built Environment, Urban Science Section. DOI: 10.3389/fbuil.2020.00148.
The COVID-19 pandemic has shocked infrastructure systems in unanticipated ways. Seemingly in the course of weeks, our demands for many basic and critical services have radically shifted. With expected long-term effects (i.e., years), COVID-19 is going to have profound impacts on every facet of infrastructure systems, and will shock these systems very differently than the hazards that we often focus on, such as extreme events, disrepair, and terrorist attacks. At the beginning of this pandemic, infrastructure managers are scrambling to respond to changes in demand, and to understand what the long-term effects are for how they operate and maintain their systems. We contend that COVID-19 is revealing several important limitations to how we approach and manage our infrastructure, that must be acknowledged and addressed as the pandemic persists, and in a future increasingly characterized by accelerating and increasingly uncertain conditions. These limitations are how (i) we prepare for concurrent hazards, (ii) frame criticality based on traditional infrastructure sectors and not human capabilities, (iii) we emphasize efficiency at a cost to resilience, and (iv) leadership is largely focused on stable conditions. Each of these challenges represents a call for major rethinking for how we approach infrastructure, and COVID-19 presents a window of opportunity for change.
Helmrich, A. and Chester, M. (2020). Reconciling Complexity and Deep Uncertainty in Infrastructure Design for Climate Adaptation. Sustainable and Resilient Infrastructure. DOI: 10.1080/23789689.2019.1708179.
As climate change is emerging as a major challenge for man-made systems in the coming century, there has been significant effort to understand how to position infrastructure to adapt and deliver services reliably. Particularly, the climate is changing faster than the expected lifetime of critical infrastructure, resulting in situations well beyond the intended design conditions of a stationary climate. This study assesses how well existing infrastructure design approaches – traditional fail-safe, armoring, low regret, safe-to-fail, and adaptive management – account for climate-related complexity and uncertainty through an application of the Cynefin and Deep Uncertainty Frameworks. The results indicate that existing infrastructure design approaches have varying levels of validity for addressing climate change across spatial and temporal scales. The most common infrastructure design approaches undertake lower levels of complexity and uncertainty than climate change demands, indicating the potential of approaches that address complexity and deep uncertainty have not been fully realized.