Extreme floods of Venice: characteristics, dynamics, past and future evolution (review article)

Abstract. Floods in the Venice city centre result from superposition of several factors: astronomical tides; seiches; and atmospherically forced fluctuations, which include storm surges, meteotsunamis, surges caused by atmospheric planetary waves. All these factors can contribute to positive water height anomalies individually increase probability extreme events when they act constructively. The largest heights are mostly produced sirocco winds, leading a characteristic seasonal cycle, with most frequent occurring November March. Storm be cyclones whose centres located either north or south Alps. Historically, intense have been cyclogenesis western Mediterranean, west main cyclogenetic area Mediterranean region Gulf Genoa. Only small fraction inter-annual variability is described fluctuations dominant patterns circulation over Euro-Atlantic sector. Therefore, decadal extremes remain largely unexplained. In particular, effect 11-year solar cycle does not appear steadily present if more than 100 years observations considered. historic frequency floods since mid-19th century explained relative mean sea level rise. Analogously, future regional rise will important driver increasing duration intensity through this century, overcompensating for projected decrease marine storminess. covers wide range, reflecting highly uncertain mass contributions melting Antarctica Greenland ice sheets, especially towards end century. For high-emission scenario (RCP8.5), magnitude 1-in-100-year values at northern Adriatic coast 26–35 cm 2050 53–171 2100 respect value subject continued thereafter. moderate-emission (RCP4.5), 12–17 24–56 2100. Local subsidence (which included estimates) further heights. This analysis shows need adaptive long-term planning coastal defences using flexible solutions that appropriate across large range plausible extremes.