Storm Surge Threats: Assessing İzmir’s Transportation Network Vulnerabilities

Coastal cities are increasingly vulnerable to climate-related hazards – storm surges, sea-level rise, and extreme weather – which threaten transportation systems. Recent disasters highlight the urgent need for resilience planning. This study evaluates the vulnerability of İzmir’s transportation network under three storm surge scenarios by integrating high-resolution spatial data, IPCC (Intergovernmental Panel on Climate Change) projections, and historical flood records. The analysis applies an indicator-based approach grounded in the IPCC framework, evaluating vulnerability as a function of exposure, sensitivity, and adaptive capacity. Findings show water intrusion ranging from 330 to 12,000 meters across İzmir Bay, significantly impacting critical infrastructure. Tram lines and ferry piers are most affected, with over 84% and 97% of assets classified as highly or very highly vulnerable. Metro stations (52%) and segments of the İZBAN rail system (34%) are also at risk, particularly in low-lying coastal zones. These disruptions threaten urban mobility, economic stability, and emergency response. The current research provides a spatially explicit vulnerability assessment of İzmir’s transport infrastructure under different storm surge scenarios, identifying the most at-risk assets and locations. By applying an indicator-based framework, it quantifies vulnerability in a systematic way and highlights the urgency of targeted adaptation in central districts like Konak and Karşıyaka. The findings offer actionable insights for urban planners and policymakers, emphasizing the need to integrate Nature-based Solutions and engineered protections in areas with low elevation and critical transport functions. The methodological approach can also be adapted to support resilience planning in other coastal cities facing similar climate threats.