Coastal flooding is a danger to people who live near coasts. It is therefore necessary to increase knowledge of the causes of coastal flooding through scientific research. Furthermore, the correct assessment of flooding areas is very important for the management of coastal areas. Given this, the current European legislation (Directive 2007/60/EC) requires flood areas to be mapped, but to date in Italy each region is still adopting different procedures to map their flood areas. This paper, through two case studies, analyzes the hazard, damage and risk mapping of coastal flooding areas. The cases are related to two Calabrian towns, located along the Ionian coast (Monasterace), and the Tyrrhenian coast (Scilla), with both particularly prone to coastal flooding. In particular, with regards to the hazard mapping, the effects of sea storms and climate changes were taken into account. The damage assessment followed an "ex ante" approach, based on the employment of land use maps, in accordance with current Italian legislation. Furthermore, risk maps were added, and obtained by combining both damage and hazard maps. Finally, a comparison with previous events allowed us to verify the validity of the proposed methodology.

Coastal flooding is a topic of particular interest both in scientific research and for public administration. In fact, effective management of both coastal erosion and coastal flood risk requires a mapping of flooding areas by current European legislation (Directive 2007/60/EC). Regarding Italy, coastal erosion is widely studied and mapped, but coastal flooding has not been uniformly examined across all regions. This paper analyses the main factors that influence coastal flooding, being mainly tidal excursion and run-up, and a new methodology is proposed for the classification of storm damage based on the effects produced by the coastal wave action. In fact, six classes of damage have been defined, sorted by increasing severity, namely: traffic interruption, infrastructure damage, maritime works damage, erosion of beaches and dunes, flooding to homes, and a combination of these various factors. The new classification was applied to two case studies, both in Calabria (Italy): Scilla on the Tyrrhenian coast, and Monasterace on the Ionian coast. The two locations were chosen because in Scilla the coastal morphology makes it particularly subject to storms that overreach the beach and reach local houses, even those located upstream of the seafront. In Monasterace, on the other hand, there is an important archaeological site on a coastal dune that, over the years, has often been damaged by sea storms. The analysis of the events was conducted starting with data present in the A.Si.Cal. (Historically flooded areas in Calabria) of the CNR-IRPI of Cosenza, which containing data relating to events of hydrogeological instability, including sea storms which have occurred in Calabria over the last few centuries, and from the MeteoCean group of the University of Genoa, which contains wave data for the period 1979-2017, which is reconstructed from the Climate Forecast System Reanalysis (CFSR) data.

<p>In Mediterranean environments, where soil erosion rates are often not tolerable, sediment connectivity at the watershed scale needs accurate evaluation tools. Quiñonero-Rubio et al. (2013) proposed the Catchment Connectivity Index (CCI) to describe hydrological and geomorphological factors. It requires the combination of considerable skills to data sources and demanding field surveys. In order to improve the index and to simplify its application, in this study we propose a modified version of the CCI, the mCCI, that produces a more efficient description of the hydrological and geomorphological parameters composing CCI and, thanks to the large use of GIS software, making easier its applicability for operators with less field experience.</p><p>The mCCI is applied in a torrent of Calabria (Southern Italy) to evaluate the sediment connectivity at the catchment scale, by comparing four scenarios: a combination of check dam presence or not and land use or not, in 1955 and in 2012. This case study has shown how and by what extent the natural and human impacts (climate and land-use changes and check dam installation) have affected the geomorphic processes influencing sediment circulation in the studied basin throughout six decades. From 1955 to 2012, a general decrease in sediment connectivity has been caught by the mCCI, as a result of the combined effects of greening-up processes of the catchment (due to both natural afforestation and human-induced reforestation) and the installation of check dams, which have decreased the catchment potential to circulating sediments. Overall, the mCCI can be used as an analytical tool to evaluate the influence of past or future changes in natural and human-induced changes in land use and climate actions to give support to land planners in watershed management tasks.</p>

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