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Wyszukujesz frazę "coastal sediment" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Application of two coastal profile evolution models to Lubiatowo, Poland and La Barrosa, Spain
Autorzy:
O'Hare, T. J.
Ostrowski, R.
Emsley, S. M.
Huntley, D. A.
Powiązania:
https://bibliotekanauki.pl/articles/240970.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
beach
coastal profile model
hydrodynamics
sediment transport
Opis:
Two contrasting coastal profile models are applied to three bathymetries including a uniform gradient beach and natural profiles (multi-barred and multi-stepped) obtained from Lubiatowo, Poland and La Barrosa, Spain. The first model, developed at the Institute of Hydro-Engineering of the Polish Academy of Science (IBW PAN) (Poland), couples a quasi-3D model for nearshore hydrodynamics with a quasi-phase resolving sediment transport model which considers transport in the bed load, contact load and outer layers. The second model (PLYMPROF), developed at the University of Plymouth (UK), couples a relatively simple wave transformation model with a new abstracted description of cross-shore sediment transport beneath waves. A variety of model simulations are described, including simple runs with uniform wave forcing (up to 50 days in duration using PLYMPROF) and runs with parameterized wave forcing (wave height and wave period in deep water) for periods with one or two storm events (6-11 days total duration). Both models coped well with the different initial profiles and with uniform and time-varying wave conditions. The results of the simulations suggest that onshore-directed sediment transport in the shoaling and outer surf zones is dominant for the cases considered. Compared to the IBW PAN model, the PLYMPROF model results (using coefficients from a separate study of bar evolution at Duck, USA) show larger offshore-directed transport in the inner surf zone associated with return flow, with the overall sediment transport pattern located considerably closer to the shore. Alteration of a single coefficient in the PLYMPROF model shifts the predicted transport pattern seawards, but also results in enhanced offshore-directed transport. Despite differences in predicted cross-shore sediment transport the two models produced surprisingly similar trends in overall profile evolution suggesting that feedback between existing bathymetry and the sediment transport pattern may exert a major control on profile development. Results also suggested that bar migration patterns cannot be simply related to the occurrence or absence of storm conditions, but rather depend more subtly on the exact placement of wave breaking locations in relation to existing bars. Incorporation of tidal water level variations for La Barrosa produced small changes in model predictions, with tidal migration of the sediment flux pattern suppressing the development of bar morphology in line with the form of the observed profile.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2006, 53, 3; 235-266
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationships between coastal processes and properties of the nearshore sea bed dynamic layer
Autorzy:
Ostrowski, R.
Pruszak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/47468.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic coast
Baltic dune
cliff
coastal process
coastal zone
geomorphological condition
hydrodynamic impact
Polska
sandy sediment
sediment transport
Opis:
The paper discusses the notion of a layer of sandy sediments overlying a substratum of cohesive deposits in the coastal zone. This layer of sand is generally more mobile and is therefore conventionally referred to as the dynamic layer. Its parameters are important to coastal lithodynamic and morphodynamic processes caused by waves and currents. On the other hand, the dynamic layer is formed by nearshore hydrodynamic impact. The variability of the features of the dynamic layer on the southern Baltic dune and cliff shores in Poland is analysed on the basis of selected geological data supported by local seismo-acoustic field investigations. It appears that the conventional notion of the dynamic layer makes sense only in specific geomorphologic conditions. In such cases, mostly related to cliff shores, theoretical modelling of sediment transport should take the properties of the dynamic layer into account.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling longshore sediment transport under asymmetric waves
Autorzy:
Ostrowski, R.
Szmytkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/49027.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
coastal zone
hydrodynamic condition
sandy sediment
wave-current interaction
sediment transport
wave asymmetry
Opis:
Two wave theories are applied in calculations of longshore sediment transport rates: the second Stokes approximation and the cnoidal theory. These approaches are used to model sand motion in nearshore locations beyond and within the surf zone. Wave-current interaction in the nearbed layer and bed shear stresses are solved using a momentum integral method, whereas sediment transport is described by a three-layer model encompassing bedload, contact load and suspended load. Computational results for asymmetric waves are compared with the results obtained using linear wave theory and the conventional sediment transport models of Bailard (1981), Bijker (1971) and Van Rijn (1993).
Źródło:
Oceanologia; 2006, 48, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Driving forces of sandy sediment transport beyond the surf zone
Autorzy:
Stella, M.
Ostrowski, R.
Szmytkiewicz, P.
Kapinski, J.
Marcinkowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/47878.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sandy sediment
sediment transport
surf zone
wave-current interaction
roughness
coastal zone
Baltic Sea
Źródło:
Oceanologia; 2019, 61, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of Klaipeda Port entrance channel dredging on the dynamics of coastal zone, Lithuania
Autorzy:
Zilinskas, G.
Janusaite, R.
Jarmalavicius, D.
Pupienis, D.
Powiązania:
https://bibliotekanauki.pl/articles/2079089.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Klaipeda Port
Southern Baltic
Lithuania
entrance channel
dredging
coastal zone
sediment transport
lithodynamic condition
coastal erosion
Opis:
Dredging entrance channels to ports on open littoral drift seashores often causes major morphological changes to the shoreline. This study aims to assess the impact of dredging the Port of Klaipėda's entrance channel and the construction of the jetties on the coastal zone. Based on an analysis of cartographic material collected between 1835 and 2017, and on field data (bathymetric surveys and cross-shore profile levelling), changes to the coastal zone in the area nearest to the port were evaluated. The dominant longshore sediment transport on the Lithuanian nearshore runs from south to north. Thus, based on established patterns, intensive accretion could have been expected to take place on the southern side of the port jetties and erosion on their northern side. However, in the case of the Port of Klaipėda, in the area nearest to the port on the updrift side of the port jetties, where accretion would have been expected to take place, the nearshore depth increased throughout the 20th century (when the length and configuration of the jetties did not change). The shoreline shifted landward instead of moving further out to sea. The present study shows that the intensive dredging of the entrance channel caused nearshore and shore erosion on the updrift side of the port jetties, even while a sufficient sediment load was being transported by the longshore drift.
Źródło:
Oceanologia; 2020, 62, 4PA; 489-500
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling nearshore hydrodynamics and circulation under the impact of high waves at the coast of Varkiza in Saronic-Athens Gulf
Autorzy:
Belibassakis, K.A.
Karathanasi, F.E.
Powiązania:
https://bibliotekanauki.pl/articles/47934.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sediment transport
shoreline
modelling
hydrodynamics
Saronic Gulf
coastal zone
wind
wave
Opis:
A plethora of physical parameters, such as hydro-, litho- and morpho-dynamic char- acteristics, are essential for understanding the response of coastal systems to intense sea states in terms of sediment transport and shoreline evolution. Nowadays, numerical models are extensively applied to meet the above needs and support coastal planning and management. In the present work, a 2DH dynamic modelling system is used for simulating the hydrodynamic and meteorological/ oceanographic characteristics of the Saronic Gulf, in order to examine circulation patterns and predict sediment transport phenomena under high wave conditions at the coast of Varkiza, a sandy beach in the southern Attica, Greece. Time series of wind and wave data were used as input at the open boundaries of the model domain while the model was calibrated and validated through (linear and directional) statistical measures with respect to in situ wave measurements, since there was lack of hydrodynamic data at the site of interest.The simulation period of the model was between January 3 and February 19, 2013, with consecutive high waves in-between. The good agreement of the numerical results from the wave and hydrodynamic model with in situ measurements confirmed the suitability of the model for the support of sediment transport rates at Varkiza coastal segment. Model results reveal that there is a counter-clockwise water circulation during high waves that contribute to the erosion of the examined beach, which is also confirmed by independent field measurements.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the climatic variations in the wind waves parameters on the alongshore sediment transport
Autorzy:
Divinsky, B.V.
Kosyan, R.D.
Powiązania:
https://bibliotekanauki.pl/articles/2079275.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
climate variability
wind wave
coastal zone
sediment transport
numerical modelling
Black Sea
Opis:
The purpose of this work was to analyze the influence of climatic variability of wind waves and swell parameters in the coastal zone on the sediment transport and to assess the contribution of the swell to the formation of alongshore fluxes. The object of research is the Anapa bay-bar (the Black Sea). Mathematical modeling has shown that in the Anapa bay-bar area the average annual wind waves and swell powers have significant interannual variability. For the period from 1979 to 2017, in the southern part of the bay-bar, there was a statistically significant decrease in the share of swell in the alongshore transport, directed from NW to SE, in the central part – an increase in the contribution of swell to the total sediment flow from SE to NW, in the northern part – probable increase in flows to NW and decrease – to SE. Such a dynamic is consistent, in general, with experimental observations of the processes of erosion and accumulation of beach-forming material along the Anapa bay-bar coastline. A separate description of the bottom sediment fluxes under the influence of wind waves and swell made it possible to explain the fluctuations of the coastline over a climatic period.
Źródło:
Oceanologia; 2020, 62, 2; 190-199
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Longshore sediment transport at Golden Sands (Bulgaria)
Autorzy:
Nikolov, H.
Trifonova, E.
Cherneva, Z.
Ostrowski, R.
Skaja, M.
Szmytkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/48714.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
coastal zone
wave refraction
wave diffraction
Black Sea
sandy beach
sediment transport
Golden Sands
Bulgaria
Opis:
The paper presents the results of studies on the qualitative and quantitative features of the littoral drift at Golden Sands (Bulgaria), carried out jointly by Polish and Bulgarian researchers. The mathematical modelling of physical coastal processes took wave transformation (wave diffraction and refraction; the effects of shoaling and wave breaking) and longshore sediment transport into account. The computations were carried out for the mean statistical annual wave climate, determined on the basis of IO BAS wave data, simulated using the WAM method from long-term Black Sea wind data. The results of sediment transport computations clearly show that its direction off the Golden Sands shore is from north to south.
Źródło:
Oceanologia; 2006, 48, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A quasi phase-resolving model of net sand transport and short-term cross-shore profile evolution
Autorzy:
Ostrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/48565.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
coastal zone
hydrodynamics
wave-current condition
cross-shore profile
Baltic Sea
evolution
modelling
sand transport
sediment transport
hydrodynamic impact
Opis:
A way of modelling of the net sediment transport rate on a cross-shore profile and the resulting sea bed changes is presented. In the sediment transport computations, a three-layer model with a description of the bedload based on the water-soil mixture theory by Kaczmarek& Ostrowski (1998, 2002) is used. The modelling system is applied to wave-current conditions variable over the cross-shore profile, and determined using the computational frameworkof Szmytkiewicz (2002a, b). The sediment transport module incorporates the asymmetric wave approaches as proposed by Ostrowski (2002). Model simulations have been produced for uniformly sloped and multi-bar initial cross-shore profiles. Some of the model results are compared with the IBW PAN (Institute of Hydroengineering of the Polish Academy of Sciences) field data collected at the Coastal Research Station in Lubiatowo.
Źródło:
Oceanologia; 2003, 45, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of the sandy coast: Hydrodynamic and morphodynamic conditions (on the example of the Eastern Gulf of Finland)
Autorzy:
Divinsky, B.V.
Ryabchuk, D.V.
Kosyan, R.D.
Sergeev, A.Y.
Powiązania:
https://bibliotekanauki.pl/articles/2078924.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sandy coast
coastal zone
climate change
hydrodynamic condition
morphodynamic condition
sea level
surface wave
sediment transport
numerical modelling
Finland Gulf
Opis:
Forecasting the coastal zone development under possible climatic changes and technogenic impact is an extremely important task. This forecasting is based on our understanding of the mechanism of the hydrodynamic processes impact on the coastal zone. The goal of this work is to describe the hydrodynamic conditions (currents, sea level, surface waves) of coastal waters and to assess the influence of hydrodynamic parameters on the general dynamics of the beach. The object of this study is a part of the southern coastal zone of the Gulf of Finland (Baltic Sea). The method of research is a full-scale experiment and mathematical modeling. The initial data for the analysis are climatic characteristics of the hydrodynamic regime of the sea (velocity and direction of currents, sea level, integral parameters of wind seas and swell), as well as interannual variations in the position of the coastline in the region of the Izhora village in the eastern part of the Gulf of Finland. Interannual variations in hydrodynamic parameters and volumes of bottom material transported under the influence of wind seas and swell were estimated. Main conclusion: swell waves determine the general background in the patterns of the bottom material transport, and the contribution of wind seas is in the formation of beach properties, namely, the accumulation or decrease of beach material
Źródło:
Oceanologia; 2021, 63, 2; 214-226
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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