Sandy beach evolution under the climate change and increasing anthropogenic pressure: Eastern Baltic Sea case

Port of Klaipeda is located in the complex hydrological system, between Curonian lagoon and Baltic Sea, at the Klaipeda strait in the Eastern part of the Baltic Proper. With almost 300 m of jetties separating Curonian spit and mainland coast, in that way interrupting main patch of sediment transport over all Eastern coast of the Baltic Sea. Results of the Port of Klaipeda reconstruction in 2002 and beach nourishment project, which was started in 2016, were observed on the shoreline position change. Shoreline position measurements for various time periods can be used to derive quantitative estimates of the rate of shoreline change (erosion or accretion). These rates can be used to further our understanding of the magnitude and timing of shoreline changes in a geologic or socio-economical context. In this work we will analyze shoreline position changes before and after port of Klaipeda reconstruction in 2002. We take positions of historical shorelines from various sources (aerial photos, orthophotos, topographic maps and field works) and then overlay them to produce historical shoreline maps for the 1980-2019 time period. The rates of shoreline changes have been assessed by using Digital Shoreline Analysis System (DSAS), an extension of ArcGIS. Changes in the quasi-equilibrium shoreline position changes are discussed in terms of the coastal engineering works, which have seen the elongation of the Port of Klaipeda groins and deepening of entrance channel. Nevertheless, if in the long-term (1980–2018) perspective coast is erosive and eroded coast length increase from 2.75 to 5.30 km in the last few years, the tendency of coast development has been changed. Coastal accumulation processes have been restored by the Port of Klaipeda executed coastal zone nourishment project.