Assessment of Transportation System Disruption and Accessibility to Critical Infrastructure During Flooding: Swords, Ireland Case Study

Natural disasters, such as flooding, can cause significant social, environmental, and economic damage to communities. Transportation infrastructure plays a crucial role in flood response and recovery, but flooding can disrupt road functionality, leading to both direct and indirect negative impacts, including loss of access to essential services.

This paper presents a case study on the impact of flooding on transportation networks and the accessibility of critical amenities, such as health centers and fire stations, in Swords, Ireland. Using network analysis methods, including shortest path and criticality analysis, the study evaluates how flooding disrupts access from each small area (SA), defined as the lowest level of geography for statistical purposes, to these key services. Specifically, the analysis focuses on the accessibility of health centers and fire stations, assessing travel time indicators and road criticality to identify areas that become more vulnerable during flooding.

The study considers flood risk zones, including Flood Zone A (high risk of flooding with a greater than 1% chance of river flooding) and Flood Zone B (moderate risk of flooding with a 0.1% to 1% chance of river flooding). The methodology supports the development of a real-time decision support system, allowing decision-makers to explore different flood scenarios and identify vulnerable areas and populations. This approach can inform strategies for mitigating road network failures, such as temporarily relocating critical services and improving flood resilience. The results reveal varying impacts on road networks due to different environmental conditions, with significant losses in both road segments (edges) and access points (nodes), affecting critical service accessibility. In Flood Zone A, 6 critical locations were found to be inaccessible, while in Flood Zone B, this number increased to 15. The findings highlight the risk that many essential services in the area face during flooding. This research provides valuable insights for guiding infrastructure investments and hazard mitigation strategies to enhance community resilience and ensure equitable access to critical services during flood events.