Simulated and observed reversals of wave-driven alongshore sediment transport at the eastern Baltic Sea coast

Abstract

This paper aims to analyse the sensitivity of patterns of numerically simulated potential sediment transport along the eastern Baltic Sea coast. The study area extends from the Sambian (Samland) Peninsula to Pärnu Bay in the Gulf of Riga. The magnitudes of net and bulk transport depend largely on how the shoaling and refraction of the waves are resolved. The qualitative patterns of net and bulk sediment transport are almost insensitive with respect to the details of wave transformation in the nearshore and with respect to grain size. The overall counter-clockwise transport along the study area contains two persistent reversals along the coast of the Baltic Sea proper and two frequently recurring reversals along the eastern margin of the Gulf of Riga. Individual years with normal levels of wind speed may host completely different patterns of sediment transport. The location of the most persistent convergence and divergence areas of the net transport acceptably matches the granulometric composition of the nearshore seabed up to a few km from the shoreline.

Non-cohesive Soil Direct Shear Strength Affected with Hydrostatic Pressure

“…Tyrimų vieta yra kontinentinio sektoriaus pietuose, t. y. Klaipėdos šiaurėje. Šioje vietoje (Bitinas et al 2005;Viška, Soomere 2013), priekrantėje, yra nedidelė smėlio juos ta (mIV), kuri tęsiasi maždaug iki 4-5 m gylio, giliau slūgso moreninės nuogulos (g II-III) (Skuodis 2015). Vėlyviausios jūrinės nuosėdos (mIV) sudarytos daugiausia iš žvyringo, vidutinio rupumo ir smulkaus smėlio (Dundulis et al 2006).…”

Inverse Gaussian distribution of wave set-up heights along a shoreline with complicated geometry

“…First of all, the set-up height strongly depends on the approach angle of waves at the actual breaker line. This angle is well-defined only if the coastline is almost straight, the nearshore is homogeneous in the alongshore direction and the wave field is monochromatic (Larson et al, 2010;Viška and Soomere, 2013;Lopez-Ruiz et Earth Syst. Dynam.…”

“…Several studies have focused on maxima of wave set-up over extended areas (O'Grady et al, 2015;Soomere et al, 2013) or the maxima of the contribution from wave set-up to water level extremes (Pindsoo and Soomere, 2016). This problem is relatively simple on comparatively straight open ocean coasts that are fairly homogeneous in the alongshore direction and where the highest waves tend to approach the shore under relatively small angles.…”

“…This problem is relatively simple on comparatively straight open ocean coasts that are fairly homogeneous in the alongshore direction and where the highest waves tend to approach the shore under relatively small angles. These features make it possible to use 10 simplified schemes for evaluation of the impact of refraction and shoaling in the nearshore (e.g., Larson et al, 2010) or to assume that waves propagate directly onshore (O'Grady et al, 2015), and to reduce the problem to an evaluation of the properties of highest waves from a relatively narrow range of directions (Soomere et al, 2013). In areas with complicated geometry and especially in coastal segments where high waves may often approach under large angles to the shoreline it is necessary to take into account full refraction and shoaling in the nearshore (Viška and Soomere, 2013;Pindsoo and Soomere, 15 2015).…”

Wave-induced bedload transport – a study of the southern Baltic coastal zone

“…For example, Cieślak (1985) presented the direction of fluxes along the Polish coast. Data for the eastern coast of the Baltic Sea, from the Sambian Peninsula to Pärnu Bay, were represented by Viška & Soomere (2013). Such research estimates the total volume of sediments that are transported alongshore.…”