Insights on the Extreme Storm Surge Event of the 22 November 2022 in the Venice Lagoon

Abstract

The Italian Institute for Environmental Protection and Research (ISPRA) manages the national sea state real time monitoring system for Italy, which consists of the National Sea Level Network (RMN), the North Adriatic and Venice Lagoon Sea Level Network (RMLV), the National Wave Networks (RON), and a marine weather forecasting system. These systems are particularly deployed to monitor and predict storm surges that affect the northern part of the Adriatic Sea and the Venice Lagoon, usually causing damages and morphological impacts over the highly anthropized coastal areas. On 22 November 2022, an extreme storm surge event occurred in the northern Adriatic Sea, producing severe damages on its coastline. Venice and the surrounding urban settlements have been protected from flooding thanks to the operation of the Mo.S.E. (Modulo Sperimentale Elettromeccanico) system, a set of artificial barriers built to isolate the lagoon from the sea in case of extreme high tides. Coastal flooding prevention measures, such as storm-surge barriers, are indeed being widely adopted globally because of the accelerating rise in sea levels. An analysis of this extreme event is presented here to highlight the functionality and the usefulness of the ISPRA sea state monitoring system. In particular, the analysis of the as-if scenario reproducing the natural tide propagation within the lagoon, neglecting the operation of the Mo.S.E. system, can only be pursued by using hydrodynamic models forced using extensive observed data. Results highlight that the “not-regulated” sea level would have exceeded 200 cm above the reference datum at Chioggia, a threshold never recorded in the Venice Lagoon since sea level monitoring systems have been operational.

Sea level and temperature extremes in a regulated Lagoon of Venice

“…As shown in Figure 10A, the MoSE is effective in protecting the City of Venice from severe flooding during storm surge events and limits the maximum sea water level to values lower than 1.2 m even in climate change scenarios. However, the southern part of the lagoon depicts peak water level values close to 1.8 m, indicating that the along-lagoon sea level gradient-due to the wind setup-is magnified when the lagoon is isolated from the sea (Mel et al, 2023).…”

Remote Measurement of Tide and Surge Using a Deep Learning System with Surveillance Camera Images

“…Unlike previous events, characterized by high storm surges associated with a low astronomical tidal range, the 2019 event showed how the in-phase concomitance of even non-extreme factors can lead to an exceptional rise in sea level. Mel et al [58] analyzed the event at the end of November 2022, associated with a persistent low pressure over central Italy which generated both Sirocco winds along the Adriatic and Bora winds over the northern Adriatic, causing storm surges of 173 cm (refer to the Punta della Salute gauge datum, ZMPS) and wave heights of up to 4.5 m at the CNR platform, located 12 m offshore from the Venice lagoon.…”

The Role of Different Total Water Level Definitions in Coastal Flood Modelling on a Low-Elevation Dune System

“…The extreme event chosen for this study occurred on the 22nd of November 2022 [44] and impacted the Emilia-Romagna region's natural and urban areas in the northern part of the coast, where the study area is located. The TWL registered by the tide gauge of Porto Garibaldi (Agenzia Prevenzione Ambiente Energia-ARPAE) reached values of 1.48 m above the MSL (Figure 3), the highest recorded values since it was installed in 2009, where 1 m was due to the storm surge [44]. The most important previous event, the Saint Agatha storm (2015), characterised by a TWL of 1.21 m at the same tide gauge, was considered by Perini et al [37] an event with a return period of 100 years.…”