Sediment transport and beach profile evolution induced by bi-chromatic wave groups with different group periods
| Autor: | Iván Cáceres, José M. Alsina, Enrique M. Padilla |
|---|---|
| Přispěvatelé: | Universitat Politècnica de Catalunya. Laboratori d'Enginyeria Marítima, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Technology
Engineering Civil Environmental Engineering 010504 meteorology & atmospheric sciences Meteorology Infragravity wave Bi-chromatic wave groups Suspended sediment concentration Ocean Engineering Geometry Surf zone SWASH ZONE Oceanography 01 natural sciences 0905 Civil Engineering Large scale experiments Engineering Wave height Coastal sediments NEARSHORE BARS 14. Life underwater Engineering Ocean DISSIPATION 0105 earth and related environmental sciences INFRAGRAVITY WAVES Science & Technology 010505 oceanography Breaking wave Sediment transport 2-DIMENSIONAL SURF BEAT Morphodynamics GRAVITY-WAVES Sediments marins -- Transport 0403 Geology Enginyeria civil::Enginyeria hidràulica marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] Wave shoaling Wave setup Bar morphology Beach morphodynamics Wave base Geology LONG WAVES BREAKPOINT BREAKING GENERATION |
| Zdroj: | UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) |
| Popis: | In this paper, large-scale experimental data are presented showing the beach profile morphological evolution induced by four different bi-chromatic wave conditions characterized by very similar energy content between them but varying the modulation period. Important differences were observed in the resultant beach profiles as a function of the wave group periods. Larger variability in the profile evolution is generally observed for larger wave group periods and, more importantly, as the wave group period increases the distance between the generated breaker bar and the shoreline increases. The measured primary wave height to depth ratio (¿) increases with the wave group period, which is consistent with the observed larger wave height at the breaking location. The primary wave breaking location is also observed at increasing distances with respect to the initial shoreline as the wave group period increases. The variation in ¿ with wave group period is related to the selective energy dissipation of the higher primary frequency component (f 1) during the wave group shoaling. Broad bandwith conditions (reduced wave group period) lead to larger dissipation of wave heights at the f 1 component relative to f 2 resulting in a reduction in the wave modulation and primary wave height at the breaking location. Suspended sediment fluxes obtained from collocated velocity and sediment concentration measurements in the surf zone showed a consistently larger contribution of the mean return flow to the suspended sediment fluxes compared with the wave group and primary wave components. The distinct beach profile evolution in terms of bar location is interpreted from an increasing distance of the mean breakpoint location and the location of maximum return flow with respect to the shoreline as the wave group period increases. |
| Databáze: | OpenAIRE |
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