Towards a Comparative Index of Seaport Climate Vulnerability: Developing Indicators from Open-Data

This work was motivated in part by Austin Becker’s 2013 dissertation, Building Seaport Resilience for Climate Change Adaptation: Stakeholder Perceptions of the Problems, Impacts, and Strategies, which surveyed global port authorities’ perceptions and plans for climate change adaptation and found a disconnect between perceptions of climate impacts and a lack of policies to address them. That work called for the development of a nationwide risk and vulnerability index for ports as a next step in the climate adaptation process for seaports. Climate change adaptation was found to be in the early planning phase for most ports globally, and assessing vulnerabilities is a recommended first step in risk-reduction. In the face of climate change impacts projected over the coming century, seaport decision makers have the responsibility to manage risks for a diverse array of stakeholders and enhance seaport resilience against climate and weather impacts. At the single port scale, decision makers such as port managers may consider the uninterrupted functioning of their own port the number one priority. But, at the multi-port (regional or national) scale, policy-makers will need to prioritize competing port climate-adaptation needs in order to maximize the efficiency of limited physical and financial resources and maximize the resilience of the marine transportation system as a whole. Such multi-port decisions can be supported by information products such as indicator-based composite indices that allow for objective assessment of relative vulnerabilities among a sample of ports. To that end, this work, consisting of three distinct but theoretically related manuscripts, advances the state of data-driven Climate Impact Adaptation and Vulnerability (CIAV) decision-support products for the seaport sector by assessing the current state of vulnerability assessments for seaports (manuscript 1), compiling and refining a set of candidate indicators of seaport climate and extreme-weather vulnerability from open-data sources for 23 major seaports of the United States’ North Atlantic region and creating and applying a Visual Analogue Scale (VAS) instrument for expert-evaluation of the candidate indicators (manuscript 2), and finally by applying the Analytic Hierarchy Process (AHP) with port-experts to weight a selection of the indicators to examine the suitability of the indicator-based vulnerability assessment (IBVA) approach and available open-data to create a composite index of relative climate and extreme-weather vulnerability for the sample of ports. The first manuscript in this work provides an overview of a variety of approaches that set out to quantify various aspects of seaport vulnerability. It begins with discussion of the importance of a “multi-port” approach to complement the single case study approach more commonly applied to port assessments. It then addresses the components of climate vulnerability assessments and provides examples of a variety of approaches. Finally, it suggests an opportunity exists for further research and development of standardized, comparative CCVA methods for seaports and the marine transportation system that can support CIAV decisions and allow decision-makers to compare mechanisms and drivers of climate change across multiple ports. When comparing vulnerabilities of multiple disparate systems such as ports in a region, IBVA methods can yield standardized metrics, allowing for high-level analysis to identify areas or systems of concern. To advance IBVA for the seaport sector, the second manuscript in this work investigates the suitability of publicly available open- data, generally collected for other purposes, to serve as indicators of climate and extreme-weather vulnerability for 23 major seaports in the Northeast United States, addressing the question: How sufficient is the current state of data reporting for and about the seaport sector to develop expert-supported vulnerability indicators for a regional sample of ports? To address this question, researchers developed a framework for expert-evaluation of candidate indicators that can be replicated to develop indicators in other sectors and for other purposes. Researchers first identified candidate indicators from the CCVA and seaport-studies literature and vetted them for data-availability for the sample ports. Candidate indicators were then evaluated by experts via a mind-mapping exercise, and finally via a visual analogue scale measurement instrument. Researchers developed a VAS instrument to elicit expert perception of the magnitude and direction of correlation between candidate indicators and each of the three dimensions of vulnerability that have become standard in the CCVA literature, e.g., exposure, sensitivity, and adaptive capacity. For candidate indicators selected from currently available open-data sources, port-expert respondents found notably stronger correlation with the exposure and sensitivity of a port than with the adaptive capacity. Results suggests that better data reporting and sharing within the maritime transportation sector will be necessary before IBVA will become feasible for seaports. The third manuscript in this work describes a method of weighting indicators for assessing the exposure and sensitivity of seaports to climate and extreme-weather impacts. To examine the suitability of IBVA methods and available data to discriminate relative vulnerabilities among a sample of ports, researchers employed AHP to generate weights for a subset of expert-selected indicators of seaport exposure and sensitivity to climate and extreme-weather. The indicators were selected from the results of the VAS survey of port-experts who ranked candidate indicators by magnitude of perceived correlation with the three components of vulnerability; exposure, sensitivity, and adaptive capacity. As those port-expert respondents found significantly stronger correlation between candidate indicators and the exposure and sensitivity of a port than with a port’s adaptive capacity, this AHP exercise did not include indicators of adaptive capacity. The weighted indicators were then aggregated to generate composite indices of seaport exposure and sensitivity to climate and extreme weather for 23 major ports in the North East United States. Rank order generated by AHP-weighted aggregation was compared to a subjective expert-ranking of ports by perceived vulnerability to climate and extreme weather. For the sample of 23 ports, the AHP-generated ranking matched three of the top four most vulnerable ports as assessed subjectively by port-experts. These results suggest that a composite index based on open-data may eventually prove useful as a data-driven tool for identifying outliers in terms of relative seaport vulnerabilities, however, improvements in the standardized reporting and sharing of port data will be required before such an indicator-based assessment method can prove decision-relevant. Overall, this body of work began with a call to develop a method to assess the relative vulnerabilities of seaports to climate and extreme-weather impacts. In the first of three manuscripts, this research identifies an opportunity to contribute to the CCVA literature for the seaport sector by piloting a multi-port vulnerability assessment method based on the use of indicators. The second manuscript in this work contributes to the field of IBVA for seaports by identifying from open-data sources and refining via expert-elicitation methods a set of expert-evaluated candidate indicators of seaport climate and extreme-weather vulnerability. This indicator-evaluation resulted in the finding that adaptive capacity is considered by port-experts as the most difficult of the three components of vulnerability (i.e., exposure, sensitivity, and adaptive capacity) to represent with quantitative data. The final manuscript of this work contributes to the body of CCVA and seaport-studies literature by building and trialing a composite-index of seaport climate and extreme-weather vulnerability based on the evaluated indicators and using AHP to generate component weights. By modeling seaport vulnerability with an indicator-based composite index and comparing results to expert expectations, this work has shown the potential of indicator-based methods to bring a data-driven approach to the CIAV decision-making process, however, results suggest that the current state of publicly available data for and about the seaport sector is not currently sufficient for a robust, expert-supported index