Wind Wave Conditions in Neva Bay

Coastal erosion caused by waves and water lever rising is a serious problem in the Baltic Sea region. The most vulnerable are areas that may be simultaneously affected by direct storm-induced surge and wind generated storm waves. An indicative example of the combination of these events is the Neva Bay at the eastern end of the Gulf of Finland where St. Petersburg is located. While Neva Bay is important water way and the construction site of the largest in Europe Passenger Terminal, signs of erosion were observed in some completed areas after strong storms. However, almost no wave data are available for the eastern Gulf of Finland. The study reports detailed analysis of measurements of wind parameters in several sites around the bay for years 2004-2009, and results were used in the SWAN model to estimate wind wave fields. Calculated significant wave heights strongly depend on wind speed while dependence on fetch was not observed. Under relatively calm conditions, the maximum significant wave height does not exceed 0.5 m. The highest (∼1.5 m) waves are generally concentrated in the central part of the bay during severe storms. For the strongest westerly winds wave height reaches 2 m. Such waves may occur in the vicinity of the coastal line and may cause coastal erosion, as it was observed in some coastal sections. Results of the study contribute substantially to the understanding of wind generated wave fields in Neva Bay and may be useful for coastal development and management.