Cross-Shore Profile Evolution after an Extreme Erosion Event—Palanga, Lithuania

Abstract

We report cross-shore profile evolution at Palanga, eastern Baltic Sea, where short period waves dominate. Cross-shore profile studies began directly after a significant coastal erosion event caused by storm “Anatol”, in December of 1999, and continued for a year. Further measurements were undertaken sixteen years later. Cross-shore profile changes were described, and cross-shore transport rates were calculated. A K-means clustering technique was applied to determine sections of the profile with the same development tendencies. Profile evolution was strongly influenced by the depth of closure which is constrained by a moraine layer, and the presence of a groyne. The method used divided the profile into four clusters: the first cluster in the deepest water represents profile evolution limited by the depth of closure, and the second and third are mainly affected by processes induced by wind, wave and water level changes. The most intensive sediment volume changes were observed directly after the coastal erosion event. The largest sand accumulation was in the fourth profile cluster, which includes the upper beach and dunes. Seaward extension of the dune system caused a narrowing of the visible beach, which has led to an increased sand volume (accretion) being misinterpreted as erosion

Storm Surges Versus Shore Erosion: 21 Years (2000–2020) of Observations on the Świna Gate Sandbar (Southern Baltic Coast)

“…A similar strong relationship (overall r = 0.66) was found between the storm surge height (H SL ) and the beach volume eroded (∆Q be ), but the correlation was stronger for the erosive that for the accumulative shore (r = 0.79 and r = 0.55, respectively). During the highest surges with H SL > 1.2 m AMSL, the average dune retreat was 3-8 m. The changes observed were very similar to those reported from other parts of the Baltic Sea coast (Basiński 1995, Suursaar et al 2003, Eberhards et al 2006, Tõnisson et al 2008, Koltsova, Belakova 2009, ryabchuk et al 2011, Kelpšaite-rimkiene et al 2021.…”

“…The wind was also responsible for small accumulation on dunes during the surges observed. In periods between the highest surges, the beach and the foredune evolve and develop again in the accumulative shore sections (Jarmalavicius et al 2016, Castelle et al 2017, Kelpšaite-rimkiene et al 2021, as was observed during the 21 years of observations on the Świna Gate Sandbar shore.…”

Natural and Anthropogenic Factors Shaping the Shoreline of Klaipėda, Lithuania

“…The K-means algorithm is a simple and popular clustering approach used in various applications [39]. It is a point-based clustering approach that starts with cluster centers located initially in arbitrary locations and goes through each stage of the cluster center to reduce the cluster error [39][40][41]…”

Coastal Morphology Assessment and Coastal Protection

“…Nuyts et al [4] clarified the trends of topographical changes in the Rossbeigh coastal barrier in Dingle Bay, Ireland, using detailed analyses of 19-year data from the global navigation satellite system, bathymetry surveying, and an external force observation system. Moreover, Kelpšaitė-Rimkienė et al [5] revealed the characteristics of the cross-shore profile change in the Palanga coast of the East Baltic Sea through the skillful analysis of topographic survey data and wind data using K-means Clustering Technique, and calculation of the cross-shore sediment transport rate.…”