Assessment of vulnerability to climate change: theoretical and methodological developments with applications to infrastructure and built environment (original) (raw)

Climate change impacts pose significant threat to our cities, built environments and infrastructure systems. Assessing vulnerability to climate change can help policymakers in incorporating climate futures in planning, better allocating adaptation resources, monitoring the effects of adaptation measures, and communicating risk and justifying policy to the public. Indicator Based Vulnerability Assessment (IBVA) has been widely used in a number of sectors because it is relatively simple to design, implement and communicate to policy makers. However, this approach faces significant difficulties from conceptual, theoretical and methodological points of view. A number of assumptions are typically made in methods used for aggregation of indicators-a linear, monotonic relationship between indicator and vulnerability; complete compensation between indicators; precise knowledge of vulnerable system by stakeholders who provide input data for the assessment exercise-none of which usually hold in reality. Aggregation approaches based on multi-attribute utility theory have stringent theoretical requirements (e.g., additive independence of indicators) that are hardly ever satisfied in the IBVA context. The goal of the thesis is to develop a new set of aggregation methods for IBVA that are better suited for the mix of indicators arising from the biophysical, institutional and socioeconomic components of vulnerability, and that can incorporate uncertainties, partial compensation and non-linearities. Following a metaanalysis of the IBVA literature in chapter 2, the thesis proposes a) a general mathematical framework for vulnerability assessment that better identifies sources of uncertainty and non-linearity; b) a new IBVA assessment methodology and computer tool based on a pair-wise outranking approach, borrowed from decision science and which foregrounds and incorporates the normative nature of some indicators, as well as partial compensation between indicators; c) a new IBVA methodology and ABSTRACT iii computer tool that can represent various sources of non-linearity in the relationship between indicators and vulnerability; and d) a system dynamics model, integrated in IBVA, for studying vulnerability of infrastructure systems and better representing the mechanistic interdependency of their components. These methods are applied to a real-life, indicator-based assessment of the vulnerability to sea-level rise of residents and infrastructure systems in Shoalhaven, south of Sydney, at local scale. The assessment is conducted in collaboration with the local council and includes an analysis of the sensitivity of vulnerability rankings to uncertainty and community preferences. In addition, the effect of using an outranking framework on the way vulnerability is conceptualized by stakeholders is critically appraised. Finally, future directions for IBVA are discussed and suggestions for further research are made. ACKNOWLEDGEMENT iv ACKNOWLEDGEMENT Undertaking this PhD has been a truly life-changing experience for me and it would not have been possible to do without the support and guidance that I received from many people. This thesis could not have been written without the support, in different ways, of my supervisor A/Prof. Abbas El-Zein. I express my sincere gratitude to him, for his kind and valuable guidance rendered to me for preparation of this thesis. His continuous encouragement, constructive advice, and contribution to improve my writing throughout this research have been of inestimable value. The joy and enthusiasm he has for his research was contagious and motivational for me I am also indebted to my annual progress review committee member, Prof. David Airey for his valuable suggestions, criticism and encouragement at various stages of the work. I acknowledge the support that I received, during the initial part of this research, from Dr. Ali El Hanandeh. The supports that I received from the Shoalhaven Council stakeholders during data collections, especially from Isabelle Ghetti, Ray