publications

2026

1. Doubling of flood-induced bridge asset failure loss in Mozambique under 2050 climate

   Yaning Qiao ,  Yaru Guo ,  Sebastian Rowan ,  Ricardo Medina ,  Xavier Espinet ,  Jonathan Cullen ,  Fanran Meng ,  and  Zhi Cao

   Global Environmental Change, 2026

   Abs

   Mozambique, often impacted by severe flooding, faces challenges with its bridge networks, particularly due to climate change. Existing methods for evaluating flood-induced bridge asset failure loss lack a comprehensive national level risk assessment that includes a full spectrum of flood events and bridge-specific details. We introduce a new framework that quantifies flood-induced bridge failure loss nationally, incorporating climate change using an equivalent flood return period approach. This framework provides a continuous risk analysis, addressing the shortcomings of discrete flood return periods. Our analysis of 1,210 bridges in Mozambique indicates an annual expected values of bridge asset failure losses equivalent to 0.6 % of its 2021 Gross Domestic Product (GDP), or 83 million dollars. Under a high emission scenario, this loss could increase to 162 million dollars by 2050. The findings highlight the vulnerability of Mozambique’s bridges to floods with return periods of 500 to 1000 years, suggesting the need for revisions of bridge design codes. The framework’s utility extends beyond Mozambique; Other Global South countries can apply it to assess their bridge asset failure risks and strategically enhance bridge resilience. This method improves infrastructure management by identifying high-risk areas and justifying resource allocation for adaptation, enabling proactive responses to flood-induced challenges and enhancing climate resilience.

2025

1. Quantifying the hidden carbon cost of floods: a stochastic and uncertainty-based valuation framework

   Sebastian Rowan ,  Erin. Bell ,  and  Weiwei Mo

   Environmental Research Letters, Dec 2025

   Abs

   Flood damage repairs to the built environment generate substantial greenhouse gas (GHG) emissions, yet these indirect climate impacts are rarely integrated into flood consequence assessments. In this study, we present a fragility-based modeling framework to estimate material replacement needs for building components damaged at specific flood depths. We develop fragility curves for each building component using a triangular cumulative distribution derived from expert judgement due to the lack of empirical data on flood losses, especially at the component level. By combining these estimates with life cycle GHG emissions for each component in a Monte Carlo simulation, we derive probabilistic, emissions-based damage curves for single-family residential structures which comprehensively account for uncertainty in the estimates. We then applied these damage curves to estimate the GHG emissions caused by a 100-year flood in two testbed regions in the Mississippi River Valley. Our results show that including the social costs of GHG emissions can increase the valuation of total flood damages by over 6%. Our results also show that flood impact estimates are highly uncertain Our model can be used by planners in cost-benefit analyses of flood risk management projects to show that such projects are more economically efficient than current methods would report.

2024

1. Enhancing Resilience: Integrating Future Flood Modeling and Socio-Economic Analysis in the Face of Climate Change Impacts

   Natalie P. Memarsadeghi ,  Sebastian Rowan ,  Adam W. Sisco ,  and  Ahmad A. Tavakoly

   Science of The Total Environment, Jul 2024

   Abs

   As climate change intensifies, future floods will become more severe in some areas with geographic variation, necessitating that local and regional governments implement systems to provide information for climate adaptation, particularly for vulnerable populations. Therefore, we aimed to develop a methodology to identify areas that are at an increased risk from future floods and independently socially vulnerable. In this study, 100-year recurrence interval flood extents and depths were estimated using an ensemble of six independent Coupled Model Intercomparison Project Phase 6 climate models for a past and future period under the highest-emissions climate scenario. The flood inundation results were related to social vulnerability for two selected study areas in the Mississippi River Basin. The range of flood extents and depths for both time periods were estimated, and differences were evaluated to determine the effects from climate change. To identify at-risk areas, the relationship between the spatial distribution of flood depths and vulnerability was then assessed. Finally, an analysis of the current and future damages on infrastructure from flooding on residential housing was performed to determine whether damages are correlated with higher vulnerability areas. Results show in every flooding scenario, flood extents and depths are increasing in the future compared with the past, ranging from an increase of 6 to 76 km2 in extent across both locations. A statistically significant relationship between spatial clusters of flooding and of vulnerability was found. The infrastructure analysis found that residential structures in the most vulnerable census tracts are 6 to 59 times more likely to experience moderate damage compared with the least vulnerable tracts depending on scenario. Overall, a framework was established to holistically understand the hydrologic and socioeconomic impacts of climate change, and a methodology was developed to use for allocating resources at the local scale.

2023

1. Operationalizing Equity for Integrated Water Resources Management

   Cydney K. Seigerman ,  S. Kyle McKay ,  Raul Basilio ,  Shelly A. Biesel ,  Jon Hallemeier ,  Andressa V. Mansur ,  Candice Piercy ,  Sebastian Rowan ,  Bruno Ubiali ,  Elissa Yeates ,  and  Donald R. Nelson

   JAWRA Journal of the American Water Resources Association, Apr 2023

   Abs

   Advancing social equity has been implicitly and explicitly central to water resources policy for decades. Yet, equity remains largely outside of standard water resources planning and management practices. Inclusion of equity within water resources infrastructure is inhibited by barriers including an incomplete conceptual understanding of equity, a perceived lack of quantitative and qualitative equity metrics, unclear connections between equity and standard project planning frameworks, and the absence of concrete examples. To facilitate greater practical inclusion of social equity in water resources practices, we describe equity relative to dimensions of distribution, procedure, and recognition and identify metrics associated with each. We then map these dimensions of equity onto different stages of a water resources project life cycle. We discuss how inequities are often perpetuated by current approaches and highlight case studies that promote one or more of the facets of equity. Rather than providing a prescriptive solution to “achieve” equity within water resources practices, we emphasize the need for contextualized approaches that include pragmatic steps toward more equitable practices and outcomes.

2022

1. New York - New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study - Tier 1 Other Social Effects/Environmental Justice Analysis

   Stephanie Galaitsi ,  Margaret Kurth ,  Sebastian Rowan ,  Elissa Yeates ,  and  Ellis Kalaidjian

   Sep 2022

2020

1. Assessing the Relationship Between Social Vulnerability, Social Capital, and Housing Resilience

   Sebastian Rowan ,  and  Kyle Kwiatkowski

   Sustainability, Sep 2020

   Abs

   Social vulnerability and social capital have been shown to influence how severely communities are impacted by natural hazards and how quickly they recover. Indices exist to quantify these factors using publicly available data; however, more empirical research is needed to validate these indices and support their use in pre-disaster planning and decision making. Using data from the Federal Emergency Management Agency and data gathered through imagery analysis in Google Earth, this study evaluates the effectiveness of two indices of social vulnerability and social capital to predict housing impacts and rates of recovery in Florida and Puerto Rico following Hurricanes Irma and Maria in 2017. We found the social vulnerability index to be statistically significant in explaining the variation of housing impacts in both case studies, with varying results for the sub-indices of social vulnerability. Results for the social capital index were mixed between the case studies, and we found no statistically significant relationship between any of the indices and rates of housing recovery. Our results show that indices such as these can be useful, with an awareness of limitations, for researchers and emergency practitioners, and additional empirical analysis is needed to more fully support their efficacy for resilience assessment.