Nearshore Observations and Modeling: Synergy for Coastal Flooding Prediction

Coastal inundation has recently started to require significant attention worldwide. Theincreasing frequency and intensity of extreme events (sea storms, tsunami waves) are highly stressingcoastal environments by endangering a large number of residential areas, ecosystems, and touristfacilities, and also leading to potential environmental risks. Predicting such events and the generatedcoastal flooding is thus of paramount importance and can be accomplished by exploiting the potentialof different tools. An example is the combination of remote sensors, like marine radars, with numericalmodels. Specifically, while instruments like X-band radars are able to precisely reconstruct both wavefield and bathymetry up to some kilometers off the coast, wave-resolving Boussinesq-type models canreproduce the wave propagation in the nearshore area and the consequent coastal flooding. Hence,starting from baseline simulations of wave propagation and the conversion of water elevation resultsinto radar images, the present work illustrates the reconstruction of coastal data (wave field andseabed depth) using a specifically suited data processing method, named the “Local Method”, andthe use of such coastal data to run numerical simulations of coastal inundation in different scenarios.Such scenarios were built using two different European beaches, i.e., Senigallia (Italy) and Oostende(Belgium), and three different directional spreading values to evaluate the performances in cases ofeither long- or short-crested waves. Both baseline and inundation simulations were run using theFUNWAVE-TVD solver. The overall validation of the methodology, in terms of maximum inundation,shows its good performance, especially in cases of short-crested wind waves. Furthermore, theapplication on Oostende Beach demonstrates that the present methodology might work using onlyopen-access tools, providing an easy investigation of coastal inundation and potential low-costintegration into early warning systems