Coastal flood hazard for Lecce, Italy, 1 from breaches in the dunes

The territory of the municipality of Lecce encompasses a long coastal strip along the Adriatic Sea, which, to date, lacks high-resolution flood hazard mapping. We used a 1-m-resolution digital terrain model (DTM), as well as extreme sea level (ESL) projections from the literature, including storm surge, wave setup, tide, and mean sea level rise. A geodetic transformation was used to refer ESL to the DTM vertical datum. The outcome was used in a bathtub model, validated via in situ photos and satellite observations. The modest elevation and gentle slope of the terrain lead to a potential long-range flooding. The northern sectors, including Spiaggiabella, Torre Chianca, and a specific site in Frigole, are identified as the areas most susceptible to coastal flooding. Gaps and damage to the dune belt, specific roads, and reclamation canals can function as ingress points for seawater during flooding events. While the results are affected by several uncertainties, we find an appreciable coastal hazard for several urban and agricultural settlements in Lecce. The study underscores the importance of territorial monitoring in shaping effective, context-specific adaptation strategies for coastal resilience along the Lecce shoreline.