Wave Climate along Calabrian Coasts

Abstract

The wave climate is highly variable temporally and spatially, depending mainly on the atmospheric conditions and on fetch extensions. Wave climate is one of the main causes of coastal erosion processes, together with anthropogenic pressure and with coastal and river sedimentary balance. Therefore, a detailed spatial and temporal knowledge of wave climate is very important in managing coastal areas and in planning coastal defense works. This paper describes an analysis of the wave climate carried out along the Calabrian coasts in over 50 areas, each of them covering an average of 15 km of coastline. For each area, over 40 years of wave data were analyzed to calculate over 20 parameters, representative of annual and seasonal average and maximum wave conditions. The large number of areas is related to the geomorphological and climatic complexity of Calabria. This analysis mainly highlighted that the two Ionian and Tyrrhenian coasts are very different from the wave climate point of view. Indeed, the Ionian coast is heavier in ordinary wave conditions, while the Tyrrhenian coast is heavier in extreme wave conditions.

Possible Increases in Floodable Areas Due to Climate Change: The Case Study of Calabria (Italy)

“…In addition, not only coastal plains and heavily anthropized areas were considered but also towns and areas characterized by infrastructures, coastal dunes, and sites of social, economic, and strategic interest. The results highlight that these peculiarities cause significant variability of weather and sea conditions among the different coastal areas, which influences the characteristics of the meteorological events and of the wave climate [70]. Furthermore, the present study is characterized by a high level of detail, both from the wave climate point of view and from the altimetry point of view, which is a key factor for accurately estimating floodable areas.…”

“…The values of this parameter are very similar to each other in the various sample areas, with higher values in the Tyrrhenian Sea than in the Ionian Sea and with an average difference between the two seas of about 0.5 m. Furthermore, Rossano and Lazzaro are exceptions, where the maximum height reached by the water referred to the average sea level are much greater than those of all the other sample areas. The higher values in the Tyrrhenian Sea than in the Ionian Sea are related to the significant differences between the two seas from the point of view of the wave climate [70]. In detail, the average and frequent wave conditions are slightly higher in the Ionian coast, while the exceptional wave conditions, such as those considered for the run-up calculation, are much greater in the Tyrrhenian coast.…”

“…These areas are characterized almost exclusively by a high coast and only a few pocket beaches. This coastal area is the easternmost of Calabria and is exposed to fetch lengths in the order of hundreds of kilometers along most directions, so it is very exposed to intense wave motion [70]. Another sample area with small floodable areas is Ricadi (Figure 5), which is a pocket beach located within the Capo Vaticano promontory on the Tyrrhenian coast but, unlike the previous two, it also has a partially flooded inhabited center.…”

Shoreline Changes Due to the Construction of Ports: Case Study—Calabria (Italy)

“…The two seas are connected by the Strait of Messina, which is in the southern part of Calabria, near the north-eastern part of Sicily. This irregular coastal morphology causes notable differences between the various coastal areas in terms of wave climate, fetch, and bathymetry, both at a macro-area level (Ionian and Tyrrhenian coasts) and at a smaller scale [64]. The Tyrrhenian macro-area is exposed to wave climate coming from the fourth quadrant (between the west and the north) and is characterized by fetch lengths up to over 700 km and depths up to approximately 4000 m, with slopes generally between 2 and 5%.…”

“…The type of sediment was evaluated based on a technical report that shows data regarding the Calabrian coast [75], in accordance with the Wentworth grain size classification [76], while the depth at the head of the breakwater updrift was estimated based on the Navionics Chart Viewer (https://webapp.navionics.com/#boating, accessed on 15 November 2023). Regarding the wave forcings, the wave climate was evaluated starting from the research of Foti et al [64] in terms of maximum significant wave height (h s,max ), average significant wave height (h s,av ), difference between the significant wave height of a return period of 1 year and the significant wave height of a return period of 100 years (∆h 1-100 ), average annual energy flux (φ), main sector (MS), and angle between the main sector and the coast in the absence of the port (α). Finally, the temporal analysis covered the period of construction of the ports, coastal protection structures, and siltation.…”