Coastal dynamics of the eastern Gulf of Finland, the Baltic Sea: toward a quantitative assessment
Alexander Sergeev, Daria Ryabchuk, Vladimir Zhamoida, Igor Leont’yev, Alexander Kolesov, Olga Kovaleva, Kaarel Orviku
Abstract The easternmost part of the Gulf of Finland is characterized by intense coastal processes dominated by wave erosion. Reliable prediction of the coastal zone development, as well as effective strategy for coastal protection, demands a quantitative assessment of beach transformation and volume of sediment loss as a result of extreme storms. The main goal of this study based on results of terrestrial laser scanning was to establish volumes of eroded, transported, and redeposited sand during storm surge events that occurred between 2012 and 2017, and to verify a mathematical model of beach profile changes within key areas located in the Kurortny District of St. Petersburg (Gulf of Finland, Baltic Sea), where the longest set of levelling and terrestrial laser scanning was conducted. The resulting detailed 3D GIS models of coastal relief, based on high-resolution geodesic surveys, produced a highly reliable database of beachface transformation under the extreme storm impact and quantitative assessment of erosion volumes and sediment loss.