Characterization of Storm Events for Coastal Flood Hazard Assessment: Sensitivity of the Spatial Structure Variable to the Number of Simulations

The authors recently proposed a method to define reliable joint statistics of significant wave heights Hs and water levels ζ in order to assess the coastal flood hazard. The method is termed Spatial Structure Variable approach and focuses on the selection of the sample pair that characterizes each sea storm, to evaluate the occurrence probability of extreme events. The pair is selected by maximizing a spatial structure variable, that is a function (a linear combination) of Hs and ζ, defined for each point of the area at risk. The structure variable represents the sensitivity of the flooding process to Hs and ζ, as found by analyzing a large set of inundation maps (90) produced through a Simplified Shallow-Water numerical model (SSW). The aim of this paper is to provide guidelines on the number of simulations required and show an application of the method for a large stretch of the coast of the Venetian region (Italy).