Wave forcing assessment at regional scale in a climate change scenario: the Sardinia case study

In recent decades, the world’s population is progressively shifting towards coastal areas and it is estimated that it could reach 1 billion by 2050. On the other hand, meteocean forcings show increasing modification, in terms of the occurrence and frequency of energetic events, related to climate change trends. Then, the definition of adaptation strategies is crucial to managing coastal areas, especially in the most densely populated or highly valued tourist and environmental areas. Meaningful long-term strategies should then be based on quantitative estimation of future scenarios in a changing climate. Although most of the studies in the literature focus on extreme events, this paper aims to assess, through synthetic indicators, whether and how average and mild energy conditions related to wave climate will vary considering the current situation compared to future projections. The study is based on the analysis of wave data. The projection of average and mild energy conditions can indeed influence, just for example, the long-term morphodynamics of sandy beaches and the quality of bathing waters. Data extracted from the Copernicus database are considered. The methodology has been applied to the case of Sardinia Island at a regional scale. Then, the aim of this paper is twofold: on the one hand, a method is proposed to evaluate the variation of average and mild wave conditions; on the other hand, it aims to apply the method to the case study of the Sardinia coastal area to highlight its feasibility. Results confirm that variations are expected. In the analyzed case study it emerges that, on average, the long-term evolution of the wave climate shows a tendency toward intensification while a decrease in the frequency of calm conditions is estimated. Moreover, changes in wave directional sectors are observed, which, from unimodal, are estimated to exhibit bimodal characteristics in particular on the West Coast of the island. The average annual number of events undergoes an increase.