A Semi-Empirical Approach for Tsunami Inundation: An Application to the Coasts of South Italy

Tsunamis in the Mediterranean Sea have been increasingly investigated recently due to past destructive events. We present a novel operational approach for evaluating tsunami-induced inundation, based on a generalization of Green's law and a chain of intermediate and small-scale simulations. At the intermediate level, simulations with a linear solver are made to identify the distribution of a novel parameter, namely α, condensing all nearshore wave transformations other than shoaling. α represents a proxy for coastal susceptibility to the tsunami impact. Small-scale modeling of coastal flooding performed at locations for which a DTM is freely available, at the Esaro river estuary (Calabria) and in Bari (Apulia), yields inundation levels that compare well with those obtained via intermediate-scale modeling, with a saving in computational time of about 41%. This demonstrates the value of α to “scale” the offshore wave input and reduce computational effort to evaluate flooding at regional scale.