## 1 Introduction  
Lagoons cover about 13% of the overall coastal zone worldwide [1]. They are ephemeral systems in a continuous evolution that respond to modifications induced by natural and anthropogenic stressors [2]. Coastal Lagoons are among the most valuable environments of the planet, providing a range of ecological, cultural and socioeconomic services [3, 4]. Due to the sensitivity of these environments, the Lagoons are susceptible to the effects of climate changes, as documented for many areas worldwide. Extreme events and the global rise of sea levels contributed to coastal inundation and ecosystem losses in the Gulf Coast of Louisiana and Carolina Outer Banks [5], to the loss of habitat of the Jamaica Bay and New York [6] and coastal erosion in Asia and Southeast Asian coasts [7; 8; 9]. In the Venice Lagoon, Northern Adriatic Sea, an inestimable cultural heritage is threatened by an increasing frequency of floods from storm surges as a result of regional and man-induced subsidence [10] and rising sea levels [11]. Hydrodynamics and sedimentary processes play a fundamental role in the evolution of lagoons [12; 13; 14]. These shallow water bodies are usually formed by a complex network of channels crossing tidal flats and marshlands. Barrier islands partially separate a lagoon from the adjacent coastal waters, while tidal inlets regulate the fluxes of water and sediment with the open sea and, in the long term, the evolution of the internal lagoon areas and the ebb-tidal deltas. Understanding the dynamics of a lagoon, including the exchanges through the tidal inlets, and their effects on the morphology, is of crucial importance for the safeguarding and management of these ecosystems from direct anthropogenic pressures and global changes [15; 16; 17]. Although many transitional environments have historic connections with human settlements, the Lagoon of Venice represents a peculiar case as large human modifications of the environment started in the 16 th century, contributing to a significant alteration of natural dynamics [16]. Today, the lagoon is becoming increasingly deeper and saltier as it slowly returns to the sea [18], and towards the end of the century, the sea level might rise dramatically, increasing the frequency of inundations, as well as increasing their duration and extent [11]. In response to the present and future threats, the last intervention was the construction of the impressive system of mobile barriers at the three inlets, known as MoSE (from the Italian acronym for \"Experimental Electromechanical Module\"). The barriers defend the city of Venice and the lagoon islands from water levels of 120 cm over the local datum (approximately 25 cm above the current mean sea level). On 3 rd October 2020, the MoSE was operated for the first time during a real flooding scenario, closing the lagoon inlets at 70 cm while the level in the open sea reached a peak of 130 cm [11]. In the next few decades, the increasingly frequent operation of the MoSE will progressively transform the lagoon into a regulated system, which will result in further changes in the hydrodynamics [19], the fluxes of sediments, contaminants and organisms [20] and wetlands morphodynamics [21]. As with most of the transitional areas, the Venice Lagoon is a constantly evolving environment, where the exchanges at the tidal inlets control biological and morphological processes influencing the functionality of the ecosystem and the patterns of erosion and accretion. The fluxes of water and sediment through the Venice Lagoon inlets have been investigated with different approaches over a wide range of temporal and spatial scales [19; 22; 23; 24; 25].