Analysis of Dune Erosion on the Coast of South Baltic Sea Taking into Account Dune Landslide Processes

Abstract

An analysis was carried out to determine the influence of landslide process at a few meters depth under the dune surface on the rebuilding of the dune. In the first step, calculations were done using the XBEACH model to determine seabed rebuilding as well as shore and dune undercutting for the assumed hydrologic and hydrodynamic conditions. Next, the obtained tachymetric profile of the dune and beach was fed into the FLAC2D program, and calculations of stress distribution, displacements and stability conditions were made. In this way, landslide movement was identified. The theoretical investigations clearly prove that waves attacking the dune not only cause surface erosion, but also trigger a landslide within the dune mass to a maximum depth of about 5 m. It results in a lowering of the dune crown by about 0.6 ÷ 0.7 m. Numerical models such as XBEACH, SBEACH or CSHORE do not take into account landslide occurrence, and thus underestimate dune erosion.

Artificial Nourishment Schemes along the Polish Coast and Lagoon Shores between 1980 and 2020, with a Particular Focus on the Hel Peninsula

“…However, only a few focused on the Polish coast. Conversely, the Polish shoreline has been extensively researched in terms of geology or aeolian processes [1,2,34]. To fulfil the purpose of this paper, we reviewed the specialised literature, the main source of which was the Library of the Maritime Institute in Gdansk.…”

“…The area experiences its most significant development during storm surges, driven by the direct impact of wind-generated waves. Consequently, abrasion processes affecting beaches, dunes, and cliffs can be observed here, and along the majority of the Polish coastline, coastal erosion tends to prevail over processes involving marine and aeolian accumulation [1][2][3][4]. One of the methods of technical coastal protection against erosion and storm flooding is artificial beach nourishment with sand imported from the seabed [5][6][7][8][9].…”

Calculation of Dune Profile Changes Generated by Hurricane: Preliminary Results

“…In addition to quasi-stable sandbars, one ephemeral sandbar in the form of a flat underwater shoal continuously migrating sea-or shorewards has been observed in the study area at a depth of ca. 1 m (about 50 m from the shore) (Szmytkiewicz and Zabuski 2017). The calculations of dune profile changes were performed in six measured profiles spaced every 100 m, referred to as profiles no.…”

Transport of Fine Sediments in MarineWaterbodies Near River Mouths: Preliminary Results

“…This factor is of particular importance during storms, when strong waves and currents remove previously deposited material off shore (e.g. Ostrowski et al 2010, Szmytkiewicz andZabuski 2017). Larger particles are deposited in the vicinity of the coast, but smaller one may remain suspended for a long time and reach the open sea.…”