Regional Flood Assessment of Bridges Using Open Data

The escalating risk of flooding attributed to climate change poses significant threats to infrastructure, particularly bridges, which are critical components of transportation networks. As severe weather events become more frequent, the damage to these structures has profound economic and social implications, impacting not only infrastructure maintenance costs but also community safety and mobility. Recent flood events have clearly shown the severe impact of extreme flooding on bridges and society. In September 2020, a major flood impacted Karditsa County in Greece causing over €30 million in direct losses due to damage to infrastructure and tens of bridges suffered substantial damage or complete failure. In July 2021 over one hundred bridges were damaged during the exceptional flood event in North Rhine-Westphalia and Rhineland-Palatinate in Germany. In September 2022, the Marche and Umbria regions in Italy were affected by an extreme flood and over 30 bridges were severely damaged. In August 2023, Slovenia also witnessed the most devastating floods ever recorded. In 2024, Europe experienced several floods caused by prolonged heavy rainfall, among which Storm Boris impacted numerous countries in Central and Eastern Europe.

Traditional assessments of resilience often focus narrowly on individual bridges, neglecting the interconnected nature of transportation networks. However, this approach overlooks how the failure of a single bridge can disrupt an entire network, amplifying the impact of natural disasters. To enhance overall system resilience, this work proposes a network-scale perspective analysis using Open Data and addressing the complexities and uncertainties associated with data gaps such as bridge characteristics, vulnerability data or accurate hazard intensity measures. The proposed approach helps to prioritise bridge structures that are particularly vulnerable to flooding and define a robust methodology for assessing network resilience concerning flood hazards.

The methodology is applied in a critical part of the road network of the Region of West Macedonia (Greece) using representative fragility functions and flood maps at regional scale. The results demonstrate the potential of Open Data as a valuable resource for conducting large-scale resilience analyses for critical infrastructure, enabling the identification of vulnerabilities and the prioritisation of interventions even in regions with limited access to proprietary or detailed data. This innovative approach not only aims to improve the understanding of network resilience in the face of climate change but also seeks to inform policymakers and stakeholders in making data-driven decisions for future infrastructure development and maintenance.