With the worldwide growing threat of flooding, assessing flood risks for human societies and the associated social vulnerability has become a necessary but challenging task. Earlier research indicates that islands usually face heightened flood risks due to higher population density, isolation, and oceanic activities, while there is an existing lack of experience in assessing the island-focused flood risk under complex interactions between geography and socioeconomics. In this context, our study employs high-resolution flood hazard data and the principal component analysis (PCA) method to comprehensively assess the social risk of flood exposure and social vulnerability in Prince Edward Island (PEI), Canada, where limited research has been delivered on flood risk assessments. The findings reveal that exposed populations are closely related to the distribution of flood areas, with increasingly severe impact from current to future climate conditions, especially on the island’s north shore. Exposed buildings exhibit a concentrated distribution at different levels of community centers, with climate change projected to significantly worsen building exposure compared to population, possibly due to the urban agglomeration effect. The most populated cities and towns show the highest social vulnerabilities in PEI, and the results reflect a relatively less complex economic structure of islands. Recommendations for research and management in the coming stage include the necessity of particular climate actions, recognizing community centers as critical sites for flood hazard responses, and incorporating flood hazards into urban planning and management to mitigate the impacts of continuous urbanization on ecosystem services for flood prevention.
