scholarly journals Wave Transformation in a Multi-Bar Surf Zone: Case Study of Lubiatowo (Poland)

2016 ◽  
Vol 63 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Yuan-Jyh Lan ◽  
Tai-Wen Hsu ◽  
Rafał Ostrowski ◽  
Marek Szmytkiewicz

Abstract The paper presents results of field and theoretical investigations of wave transformation in the surf zone near the IBW PAN Coastal Research Station in Lubiatowo (Poland, the south Baltic Sea). The study site displays multi-bar cross-shore profiles that intensively dissipate wave energy, mostly induced by breaking. The main field data comprise wave heights and cross-shore bathymetric profiles.Wave transformation is modelled theoretically by two approaches, namely the IBW PAN phase-averaged wave transformation model and the approach based on the hydraulic jump model, developed by Hsu & Lai (2009) for hydrological situations encountered under the actual conditions of two field campaigns - in 1987 and 1996. Discrepancies between the measured data and the model results are discussed. In general, the model results are in good agreement with the in-situ observations. The comparison of the field data with the computational results concerns a part of the surf zone between about 5 m water depth and the first nearshore stable bar, where the depth amounts to ca. 1.2 m.

2015 ◽  
Vol 62 (1-2) ◽  
pp. 27-39 ◽  
Author(s):  
Grzegorz R. Cerkowniak ◽  
Rafał Ostrowski ◽  
Magdalena Stella

AbstractThe paper presents results of field and theoretical investigations of a natural sandy shore located near the IBW PAN Coastal Research Station in Lubiatowo (Poland, the south Baltic Sea). The study site displays multi-bar cross-shore profiles that intensively dissipate wave energy, mostly by breaking. The main field data comprise offshore wave parameters and three cross-shore bathymetric profiles. Waveinduced nearbed velocities and bed shear stresses are theoretically modelled for weak, moderate, strong and extreme storm conditions to determine sediment motion regimes at various locations on the seaward boundary of the surf zone. The paper contains a discussion on the depth of closure concept, according to which the offshore range of sea bottom changes can be determined by the extreme seasonal deep-water wave parameters.


1988 ◽  
Vol 1 (21) ◽  
pp. 10
Author(s):  
Mitsuo Takezawa ◽  
Masaru Mizuguchi ◽  
Shintaro Hotta ◽  
Susumu Kubota

The swash oscillation, waves and water particle velocity in the surf zone were measured by using 16 mm memo-motion cameras and electromagnetic current meters. It was inferred that incident waves form two-dimensional standing waves with the anti-node in the swash slope. Separation of the incident waves and reflected waves was attempted with good results using small amplitude long wave theory. Reflection coefficient of individual waves ranged between 0.3 and 1.0. The joint distribution of wave heights and periods in the swash oscillation exhibited different distribution from that in and outside the surf zone. This indicates that simple application of wave to wave transformation model fails in the swash zone.


1995 ◽  
Vol 17 (4) ◽  
pp. 6-12
Author(s):  
Nguyen Tien Dat ◽  
Dinh Van Manh ◽  
Nguyen Minh Son

A mathematical model on linear wave propagation toward shore is chosen and corresponding software is built. The wave transformation outside and inside the surf zone is considered including the diffraction effect. The model is tested by laboratory and field data and gave reasonables results.


Author(s):  
Moon Su Kwak ◽  
Weon mu Jeong ◽  
Nobuhisa Kobayashi

In this study, the minimization of harbor oscillation using permeable breakwater was applied to the actual harbor and investigated a reduction effect by computer simulation in order to take into account the water quality problems and measures of harbor oscillation by infragravity waves at the same time. The study site is Mukho harbor located at east coast of Korea. The infragravity waves which obtained by analyzing the field data for five years focused on the distribution between wave periods of 40s and 70s and wave heights in less than 0.1m was 94percent of analyzing data. The target wave periods for minimization of harbor oscillation was 68s. The most effective method of minimization of harbor oscillation by infragravity waves was to install a detached permeable breakwater with transmission coefficient of 0.3 on the outside harbor and replace some area of the vertical wall with wave energy dissipating structure to achieve a reflectivity of 0.9 or less in a harbor. The reduction rate of amplitude shown in 27.4percent in this method.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/oDzrehaXlY8


1986 ◽  
Vol 1 (20) ◽  
pp. 53
Author(s):  
Shigeki Sakai ◽  
Kouestu Hiyamizu ◽  
Hiroshi Saeki

Transformation of irregular waves affected by opposing currents on a sloping sea bed was discussed, experimentally and theoretically. It was found that representative values of wave height, such as a significant wave height, are larger before breaking and the wave height decaying occurs more promptly in a surf zone as opposing currents become dominant, and that characteristics of a irregular wave transformation are determined by the dimensionless unit width discharge q* and the deep water wave steepness. This means that the effects of opposing currents on irregular wave transformation are qualitatively identical to that on the regular waves. A transformation model of irregular waves affected by opposing currents was presented. In the model, formulations for a regular wave transformation, in which the effects of opposing currents were taken into account, were applied to individual waves defined by zero-down" cross-method from irregular wave profiles. Comparisons between experimental results and the prediction by the model showed that the present model gives a good explanation for wave height distributions and the experimental finding that the surf zone is moved offshore by opposing currents.


1982 ◽  
Vol 1 (18) ◽  
pp. 4 ◽  
Author(s):  
Hajime Mase ◽  
Yuichi Iwagaki

The main purpose of this paper is to propose a model for prediction of the spatial distributions of representative wave heights and the frequency distributions of wave heights of irregular waves in shallow-water including the surf zone. In order to examine the validity of the model, some experiments of irregular wave transformation have been made. In addition, an attempt has been made to clarify the spatial distribution of wave grouping experimentally. Especially the present paper focuses finding the effects of the bottom slope and the deep-water wave steepness on the wave height distribution and wave grouping.


2018 ◽  
Vol 103 (1) ◽  
pp. 91-108 ◽  
Author(s):  
Jia-Xi Zhou ◽  
Xuan-Ce Wang ◽  
Simon A. Wilde ◽  
Kai Luo ◽  
Zhi-Long Huang ◽  
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2016 ◽  
Vol 63 (4) ◽  
pp. 237-252
Author(s):  
Rafał Ostrowski ◽  
Marek Skaja

Abstract The paper deals with a sandy shore located on the open sea side of the Hel Peninsula in Poland (the south Baltic Sea coast). The study site displays a cross-shore profile that intensively dissipates wave energy, mostly due to breaking. The theoretical modelling of wave transformation at this site reveals specific distributions of wave heights and bed shear stresses. The sediment borrow areas, presently used and identified for future exploitation, are located inconveniently far from the periodically re-nourished shores. The paper presents the possibilities of dredging works in the coastal zone that would not disturb the natural nearshore motion of water and sediments. The results of the study can be helpful in formulating generic safety standards, at least with respect to dissipative shores of non-tidal or micro-tidal seas, like the Baltic Sea.


2021 ◽  
Vol 9 (4) ◽  
pp. 353
Author(s):  
Florent Birrien ◽  
Tom Baldock

An equilibrium beach profile model is developed and coupled with a parametric hydrodynamic model to provide feedback between the evolving morphology and the hydrodynamics. The model is compared to laboratory beach profiles evolving toward equilibrium conditions under constant forcing. The equilibrium model follows the classical approach but uses the bulk sediment transport as the governing model parameter. This approach is coupled with empirically derived and normalised sediment transport functions and a parametric surf zone wave transformation model. The dissipation predicted by the surf zone model controls the cross-shore position of the maxima in the sediment transport functions and hence the cross-shore evolution of the beach profile. Realistic beach profile shapes are generated for both erosive (barred) and accretive (bermed) beach profiles, and predictions of bar and berm position are satisfactory. With more complex normalised sediment transport functions, the model can be applied to conditions with a cyclical wave climate. However, the model concept is better associated with erosive wave conditions and further work is required to improve the link between the modelled dissipation and local transport for accretive conditions.


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