Iuliana Armaș, University of Bucharest

Vulnerability stands out as the most predictable, predictive, and modifiable component of risk, covering a wide range of interpretations and operationalisations (Armaș and Albulescu, 2025). The goal of studying vulnerability is to acquire a proper understanding of its causes, spatial patterns, and dynamics over time, ultimately informing actionable points for its mitigation. In this sense, vulnerability can be viewed as the critical link that makes hazard events progress to disasters.

In multi-risk contexts, vulnerability must be understood as multifaceted (i.e., physical, social, economic, institutional, etc. vulnerability), multi-scale (i.e., manifesting differently across scales), and dynamic (i.e., changing over time and across space) concept (Birkmann, 2013). Multi-hazard interactions further complicate the analysis of vulnerability dynamics, as vulnerability can be augmented by independent or compounded hazard impacts but also as a result of misguided mitigation measures (Albulescu and Armaș, 2024). Consequently, multi-risk assessment must account for these transformations of vulnerability, alongside changes in exposure and multi-hazard interactions.

The research conducted by the team at the University of Bucharest within the PARATUS Project holds these principles at its core, focusing on analysing vulnerability as a key component of multi-risk assessment in Romania’s capital city. The analysis is structured around a relevant multi-hazard disaster scenario, wherein a major earthquake (over 7 MW) originating in the Vrancea Seismogenic Zone triggers the failure of the Ciurel Dam at Morii Lake, as well as liquefaction and urban fires.

Starting from this multi-hazard disaster scenario, vulnerability is analysed at city scale based on an exploratory index-based spatial data analysis. The indicators are aggregated from various indices selected inductively after examining empirical data patterns. To account for the multifaceted nature of vulnerability, these indicators are structured into eight dimensions and subdimensions of spatial vulnerability, following criteria rooted in established theoretical frameworks and scientific literature (Armaș, 2012; et al., 2017). Given that indicators and indices vary in their contribution to the overall vulnerability, a Multi-Criteria Decision-Making method (i.e., the Analytical Hierarchy Process) is applied to account for their relative importance. The overall vulnerability is computed based on the weighted aggregation of composite maps of the different vulnerability dimensions under analysis, with each dimension being analysed separately.

As a supplementary research step specific to the Bucharest Case Study, a feedback session was organised to elicit stakeholder insights in support of the vulnerability analysis and to inform the calibration of the vulnerability weighting methodology. This session was part of the Third Stakeholder Workshop within PARATUS (Bucharest, October 7, 2025), which reunited stakeholders with various Disaster Risk Reduction and Management responsibilities, such as first responders, medical professionals, policymakers, decision-makers, construction experts, and representatives of insurance companies.

A structured quantitative survey was applied, asking participants to score, on a scale from 1 to 10, the previously defined vulnerability dimensions, drawing on their professional roles and responsibilities in disaster situations. Stakeholders were then invited to identify, based on their expertise and operational experience, the most influential variables within each vulnerability indicator. Finally, participants were asked to reflect on whether any relevant dimensions or variables had been omitted from the analysis. To contextualise and interpret the quantitative results, dedicated expert group discussions were subsequently facilitated. These discussions allowed stakeholders to elaborate on their survey responses, providing critical qualitative insights into the reasoning underpinning the scores assigned and enriching the analysis with explanatory depth beyond the numerical results.

This complex approach to vulnerability assessment in multi-risk contexts represents a notable scientific innovation that repositions vulnerability as the analytical axis through which interacting hazards, compounded impacts, and the effectiveness of mitigation efforts can be meaningfully understood and addressed. By treating vulnerability not as a static backdrop but as a dynamic, actionable component of multi-risk, the approach specific to the Bucharest Case Study opens new pathways for more process-oriented, conceptually robust, and decision-relevant multi-risk assessment.

References

  1. Albulescu, A. C., & Armaș, I. (2024). An impact-chain-based exploration of multi-hazard vulnerability dynamics: the multi-hazard of floods and the COVID-19 pandemic in Romania. Natural Hazards and Earth System Sciences, 24(8), 2895-2922. https://doi.org/10.5194/nhess-24-2895-2024
  2. Armaş, I. (2012). Multi-criteria vulnerability analysis to earthquake hazard of Bucharest, Romania. Natural hazards, 63(2), 1129-1156. https://doi.org/10.1007/s11069-012-0209-2
  3. Armaș, I., & Albulescu, A. C. (2025). From static to dynamic: Conceptual and operational developments of vulnerability. iScience. 28(3): 112070. https://doi.org/10.1016/j.isci.2025.112070
  4. Armaş, I., Toma-Danila, D., Ionescu, R., & Gavriş, A. (2017). Vulnerability to earthquake hazard: Bucharest case study, Romania. International journal of disaster risk science, 8(2), 182-195. https://doi.org/10.1007/s13753-017-0132-y
  5. Birkmann, J. (2013). Measuring Vulnerability to Natural Hazards: Towards Disaster Resilient Societies, 2nd edn. United Nations University Press