Climate Change and Population Aging Exacerbate Flood Risk to the Elderly in European Regions

Floods threaten human lives globally, yet the flood risk to the elderly (above 65) remains uncertain within warming climates and population aging. Hence, this study incorporated the General Circulation Model and Shared Socioeconomic Pathway projections into the hydraulic modeling framework, to analyze the flood risk to the elderly in Europe under climatic and socioeconomic changes. Results demonstrated that central Europe has experienced an increase in both surface runoff and streamflow (exceeding 50%), which have jointly contributed to intensified flooding in the major basins (Loire, Rhine, Elbe, and Danube) within the region. Among them, the Elbe basin exhibited a significant increase in 100-year flood peak (∼107%) and elderly population (∼15%), resulting in 51,300 (CI: 45,300–60,500) of the elderly population being exposed to high-hazard floods under a high greenhouse gas scenario (SSP5-8.5), with at most 58% (29,800, CI: 25,100–33,700) of them being densely settled or in low-& middle-income groups. Among aging cities, Prague was severely affected by floods, with 40%–54% of the exposed elderly in high-risk areas. Followed by Dresden and Hamburg, where up to 18% of the exposed elderly were threatened by high-risk floods. This study revealed regional inequalities induced by flood exposure within the context of warming climates and population aging. The methods and findings are expected to provide additional insights into sustainable flood risk management under global change.