Assessing the Impacts of Population Relocation Induced by Future Sea-Level Rise Scenarios on Transportation Systems in Coastal Communities

Coastal communities will be more vulnerable to floods in low-lying areas and seawater inundation as the sea levelrises. Users will have to take a detour to use alternate roads while the vulnerable roads are closed, increasing traveltime. A large amount of literature has been focused on addressing climate change and sea-level rise impacts,vulnerability, economic evaluation, and adaptation. However, few research has been conducted to study the impactsof population dynamics due to sea level rise within future transportation network modeling. This study aims to identifythe future transportation infrastructure in the 2035 model that is vulnerable to a two-foot sea level rise in the TampaBay Region, Florida. The impacts of these changes have been considered within three different relocation scenariosfor the affected population in the inundated zones. This analysis uses the two-foot Mean Higher High-Level watersurface data and the digital elevation data provided by NOAA for 2035. The findings of this study reveal how differentsea level rise scenarios could affect the future estimates of the transportation system and could potentially informfuture transportation planning decisions. The analysis found that approximately 358 lane miles of highway links willbe inundated. Moreover, the number of trips produced, and the amount of congestion generated with each scenariowere dependent on the population and employment relocation. The key recommendation of this research is toincorporate the potential impacts of population relocation due to sea level rise into transportation modeling. Generally,different scenarios for relocating population and employment generate new traffic demands, which could result intraffic congestion. Thus, transportation planners should simulate future sea level rise scenarios and evaluate theirimpact on the current transportation system. Findings from this study could help transportation planners and decision-makers identify the locations and transportation facilities that are most vulnerable to rising sea levels, allowing themto make more informed decisions about adaptation planning.