Next steps in capturing vulnerability dynamics: Introducing a connectivity-based model on systemic vulnerability to multi-hazards

Vulnerability has been acknowledged as a dynamic concept since the Pressure and Release model of Blaikie et al. (1994), as well as by other well-known models that integrate this risk component. Nevertheless, it is only within the past three years that new conceptual and operational frameworks have emerged, revitalising the study of vulnerability dynamics. To date, these efforts remain largely disconnected from the concept of systemic vulnerability, which is seldom defined in the literature or is typically restricted to the vulnerability that comes from the interconnectivity of different systems. Here, we posit that using the dynamics of vulnerability as a lens to study systemic vulnerability holds a significant potential for advancing in disaster risk research.In this study, we develop a connectivity-based Multi-hazard Systemic Vulnerability Model, drawing on our previous conceptual framework for analysing the augmentation of vulnerability due to hazard impacts and misfiring adaptation options. This framework is complemented by a tool we previously developed to capture this augmentation and provide it with the needed organisational and visual support, namely Enhanced Impact Chains. The model also integrates in-depth structural equations and multiple regressions, and it is validated through a robust validation procedure including three distinct validation procedures.The case study at hand focuses on two impactful and recent hazards that affected Romania in 2020-2021, namely river floods and the COVID-19 pandemic. To implement the Multi-hazard Systemic Vulnerability Model, we constructed five Impact Chains, three for the flood events in 2020, 2021, and 2022, one for the flood events of this entire period, and one multi-hazard Impact Chain that integrates both the hydrological and epidemiological hazards referring to 2020-2022.Key results show that vulnerability acts as both a passive (subject to change) and active (driving change) agent. It can initially contribute to hazard impacts, get augmented by them, and continue to reinforce these impacts afterwards. Another highlight is that vulnerabilities can slow down or hinder the implementation of adaptation measures. Reinforcement feedbacks are vital to understanding the progression of multi-hazards, especially forward from the point where impacts cease to be the results of hazards alone, but are amplified by systemic vulnerabilities that were left unaddressed by mitigation options or were even amplified by such measures that failed.Considering the findings from the model, we propose a new definition of systemic vulnerability: the stable core of vulnerability that persists across time and space, regardless of mitigation efforts and societal progress. This definition highlights the epigenetic nature of vulnerability, showcasing that systemic vulnerability results from the incapacity of a system to assimilate environmental changes, which initiates vulnerability augmentation and leads to positive feedback loops.Marking the first scientific work aiming to acquire an in-depth understanding of systemic vulnerability within multi-hazard contexts, this model sets the stage for developing the next generation of conceptual and operational frameworks to analyse changes in vulnerability.