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

Loreta Kelpšaitė-Rimkienė,Vitalijus Kondrat,Rimas Žaromskis,Kevin E Parnell

doi:10.3390/jmse9010038

Loreta Kelpšaitė-Rimkienė, Vitalijus Kondrat + Show 2 more

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https://doi.org/10.3390/jmse9010038

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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

Highlights

Explaining changes to nearshore coastal profiles remains a challenge for coastal researchers, where there is considerable alongshore sediment transport [1,2,3]
Changes to the underwater profile are frequently examined under controlled hydrodynamic conditions in wave flumes [4,5], with some studies incorporating the effects of structures [6]
This study examines beach changes at Palanga, Lithuania, a heavily modified beach on a tideless coast with significant longshore sediment transport

Summary

Introduction

Explaining changes to nearshore coastal profiles remains a challenge for coastal researchers, where there is considerable alongshore sediment transport [1,2,3]. Changes to the underwater profile are frequently examined under controlled hydrodynamic conditions in wave flumes [4,5], with some studies incorporating the effects of structures [6]. This study examines beach changes at Palanga, Lithuania, a heavily modified beach on a tideless coast with significant longshore sediment transport. Sediment transport is generally counterclockwise along the entire south-eastern coast of the Baltic Proper [14,15] from the Sambian Peninsula to Kolka Cape [16]. In other sections, such as along the Curonian spit, there are fine sands with well-developed bar systems. In a few places (the Curonian Spit and a short coastal section to the south-east of Kolka Cape)

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Discussion

Conclusion