The coastal flooding risk throughout the twenty-first century at the ancient city of Delos, Greece

Coastal archeological sites of high cultural heritage value are threatened by the effects of coastal flooding and erosion, due to extreme marine events, which are expected to intensify and become more frequent in the future. While climate change-induced inundation is often estimated by considering mean sea level rise and the intensification of extreme sea levels, the contribution of wave storms is frequently overlooked. The proposed approach considers coinciding and non-coinciding scenarios of mean sea level rise, extreme storm surge, tide, and extreme wave runup, and assesses the non-stationarity of all these variables, deriving thus the most essential drivers of coastal flooding in a changing climate. Moreover, through the use of global climatic scenarios, and coastal modeling, aims to produce detailed flooding maps for each examined scenario. This state-of-the-art methodology is incorporated into a novel climate-related risk assessment of coastal flooding based on the likelihood and consequence of a design flooding event, considering also site-specific aspects. The present study focuses on the coastal archaeological site of Delos, Greece—an island of exceptional archaeological significance but highly vulnerable to coastal inundation due to its low elevation and proximity to the sea. The coastal flooding risk is estimated in a high-resolution spatial analysis throughout the twenty-first century. The findings of the present analysis provide valuable insights into the natural hazard of coastal inundation at Delos, offering essential tools to protect coastal regions, and archaeological sites against flooding.