A study has identified the relationship between climate changes and the severity of Acqua Alta peaks in the lagoon city, also analyzing the contribution offered by the MoSE in protecting the Serenissima
Research recently published in the prestigious journal 'Nature Climate Atmospheric Science' highlighted the link between ongoing climate changes and the increase in the number and severity of high water phenomena in Venice, also noting the effectiveness of the MoSE adaptation system in terms of costs and benefits. The study, carried out byNational Institute of Geophysics and Volcanology (INGV) in collaboration with the Center National de la Recherche Scientifique de Paris (CNRS) andInternational Center for Theoretical Physics of Trieste (ICTP), analyzed four exceptional high water events that affected the lagoon city in 1966, 2008, 2018 and 2019, seriously damaging the cultural and economic heritage of Venice and threatening iconic places such as St. Mark's Basilica. “The results we obtained clearly highlighted the link between changes in atmospheric circulation and the increase in the severity of Acqua Alta events, underlining Venice's growing vulnerability to climate change”, explains Thomas Alberti, researcher at INGV and co-author of the study. “In particular, we turned our attention to the MoSE, the infrastructure designed to protect the city from flooding, which has proven to be effective in terms of costs and benefits in containing the effects of high water and the progressive rise in sea levels caused from global warming, which in Venice is also accelerated by the phenomenon of subsidence". Understanding with reasonable certainty the relationship between climatic events and calamitous events is fundamental for the protection of the social, economic and cultural heritage of inhabited areas. All land protection policies must be able to rely on scientific data with appropriate predictions, otherwise it would lead to unjustified alarms or (even worse) missed alarms. “Our long-term objective remains to better understand the impacts of sea level rise in Venice, even in conditions of extreme phenomena, to evaluate the possible scenarios expected in the coming years and contribute profitably to the debate on the development of strategies increasingly effective mitigation, adaptation and resilience that climate change and subsidence impose on this UNESCO heritage city"he concludes Marco Anzidei, researcher at INGV and co-author of the study. The research constitutes an important step towards improving understanding of the causes and effects linked to extreme climate events in coastal cities, providing a solid basis for implementing further monitoring and research actions.
Figure: Schematic representation of the risks for the Venice lagoon. The relationship between sea level and flooded area as a function of estimated damage (colored circles). The black dotted and dotted horizontal lines indicate significant levels of flooding corresponding to the inundation of St. Mark's Square (120 cm), the level at which walkways are needed to cross the square (140 cm) and the level at which the water will enter in the Basilica of San Marco (160 cm). The red dotted line indicates the level reached by the event of 04/11/1966 known as the "Great Flood of Venice" and studied in this work. The advert shows the position of the two tide gauge stations used to evaluate sea levels in the lagoon (Punta della Salute, yellow circle) and outside (Platform, white circle). The pink circles instead indicate the position of the MoSE barriers at the three inlets (North Dam, Malamocco and South Dam).