Valutazione della Vulnerabilità degli Ecosistemi sotto l'impatto del Cambiamento Climatico mediante l'uso di Fuzzy Logic e Bayesian Belief Network nell'area costiera di Oristano, Italia

Coastal ecosystems play a valuable role in wave and storm surges attenuation, erosion reduction, and in the longer-term maintenance of the coastal profile, but they are highly threatened by human activities and climate change. Indeed, the conservation of coastal ecosystems can provide significant benefits for coastal protection. For this reason, the primary objective of this work is to assess ecosystem vulnerability in the coastal area of Oristano (Italy) to Sea Level Rise and the impact of waves and storm surges. The work involves the collection of already available data (dynamic land cover maps, DTMs, SLR scenarios, ...) and retrieving new data (e.g., waves), as well as integrating new field data. Indeed, data includes forcing, biophysical, morphological, and socio-economic variables. The methodology consists of an integrated approach including the Fuzzy Logic and Bayesian Belief Network (BBN) to assess ecosystems’ vulnerability. The Fuzzy Logic model is used to assign weights to variables to define the degree of vulnerability in a Geographical Information Systems (GIS) environment. The probabilistic BBN-based method is used to calculate probability of vulnerability based on the causal relationships among the system’s variables. The outcomes of this work relate to an in-depth analysis of ecosystem vulnerability patterns and their distribution in relation to key variables, using a probabilistic approach to obtain robust vulnerability results. The key results identify the spatial distribution of vulnerability along the Gulf Oristano and highlight where the probability of vulnerable areas is expected to increase in terms of SLR pressure, which occurs especially in the northern portion of the Gulf. A coastal probability of vulnerability map under current and future SLR to identify vulnerability hotspots is an important product for coastal environment management, as it could provide the basis for protection and/or conservation measures to a different range of stakeholders. Based on the findings of this study, it is proven that Fuzzy- BBN approach coupled with GIS would be an efficient tool for coastal ecosystem vulnerability assessment and management purposes.