Numerical Modelling of the Wave Propagation Close to the Sacalin Island in the Black Sea

The target area of the present work is the nearshore neighbouring the Sacalin Island in the Black Sea, right off the Danube Delta and close to the Saint George branch of the Danube River. Being a newly formed island, this is a very special coastal environment. Moreover, because it has a great variety of rare fauna, the area was declared as an ecological reserve. A multilevel wave modelling system, based on the Simulating Waves Nearshore (SWAN) spectral model, was focused on the target area. In the final computational domain, with the highest resolution in the geographical space, the effect of the current induced by the Danube River outflow was also accounted for in the modelling process. The wave propagation patterns characteristic to this side of the sea, together with some parameters related to the shoreline conditions, were evaluated. Four different case studies were considered for a detailed analysis. The results provided by the modelling system revealed two antagonist processes. The first process, which is dominant, and that can be defined as a constructive process, corresponds to the waves coming from the northeast. The second process, which can be defined as a destructive process, corresponds to the conditions of extremely strong storms with waves coming from the southeast. Although such situations are quite rare, they might occur however from time to time and this is actually the case that generated in the winter of 2013 a strong penetration of the waves through the Sacalin Island changing the coastal configuration.