[雙語(yǔ)翻譯]--海洋地質(zhì)學(xué)外文翻譯--在一細(xì)沙海灘上對(duì)破碎孤立波的動(dòng)態(tài)模擬（第一部分實(shí)驗(yàn)研究）（原文）

1、Hydro- and morpho-dynamic modeling of breaking solitary waves over a fine sand beach. Part I: Experimental studyYin Lu Young a,?, Heng Xiao b, Timothy Maddux ca Department of Naval Architecture and Marine Engineering, Un

2、iversity of Michigan, Ann Arbor, MI 48109, United States b Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, United States c O.H. Hinsdale Wave Research Laboratory, Oregon Stat

3、e University, Corvallis, OR 97331, United Statesa b s t r a c t a r t i c l e i n f oArticle history:Received 12 December 2008Received in revised form 29 November 2009Accepted 13 December 2009Available online 22 December

4、 2009Communicated by J.T. WellsKeywords:tsunamisolitary wavesediment transportmobile bedmorpho-dynamic modelingwave–soil interactionThe objectives of this work are (1) to examine the mechanisms that influence tsunami ero

5、sion anddeposition mechanisms in the littoral zone via physical simulations of breaking solitary waves over a finesand beach, and (2) to provide experimental data for validation of numerical models to predict tsunamieros

6、ion and deposition processes. The experiments were carried out in a 48.8 m×2.16 m×2.1 m wave flume.The flume was instrumented to observe free surface elevations, cross-shore velocities, suspended sedimentconcen

7、trations, vertical and cross-shore pore-pressure gradients near the shoreline, and morphologicalchanges. In addition, wave–sediment interactions were observed via underwater video cameras. The resultsare systematically a

8、nalyzed to investigate the roles of wave breaking, bore runup, wave drawdown, andwave-induced pore-pressure variations on tsunami erosion and deposition processes. The studies showedthat the wave plunging on a thin layer

9、 of water prior to reaching the shoreline did not cause much sedimentsuspension, while the waterjet impinging directly on the beach entrained substantial amounts of sand. Thesuspended sediments were subsequently pushed u

10、p the slope by fluid momentum as the broken wavetransformed to a turbulent bore. A small net deposition region was observed near the maximum runup pointwhere both the flow velocity and the water depth were near zero. A s

11、ignificant amount of the sedimenttransport occurred during the wave drawdown in the form of thick sheet flow, which resulted in net erosionof the shore face and the beach. A hydraulic jump formed near the wave breaking r

12、egion toward the end ofthe drawdown, which caused most of the suspended sand to deposit in the wave breaking region.Consequently, breaking solitary waves over a sloping fine sand beach led to net erosion of the shore fac

13、e andthe beach, net deposition in a small region immediately seaward of the max excursion point, and netdeposition in the wave breaking zone.© 2009 Elsevier B.V. All rights reserved.1. IntroductionIt is well known t

14、hat tsunamis can mobilize substantial amount ofsediment deposits and produce significant morphological changes incoastal regions. The resulting scour damage can undermine buildingfoundations, roadways, embankments, under

15、ground pipelines, andother coastal structures. Thus, it is crucial to understand and to predictgeomorphical changes associated with tsunamis to guide futureplanning, design, and development of coastlines and coastal infr

16、a-structures. It is also important to understand the tsunami erosion anddeposition processes in order to infer the frequency and intensity ofpast tsunamis based on sedimentary records.The objectives of this paper are to:

17、 (1) examine the mechanismsthat influence tsunami erosion and deposition in the littoral zone viaphysical simulations of breaking solitary waves over a fine sand beach,and (2) provide experimental data for validation of

18、numerical modelsto predict tsunami erosion and deposition processes.1.1. Tsunami vs. wind-generated wavesTsunami is generally defined as long period waves generated by anunderwater earthquake, submarine landslides, volca

19、nic eruptions, orastroid impacts. Due to their long periods, tsunamis are often modeledas solitary waves in physical and theoretical studies. The high flowvelocity (up to 20 m/s), large flow depth (up to 30 m or more), a

20、ndlong wave period (of the order of hundreds to thousands of seconds)of a major tsunami can erode, suspend and transport a large volume ofsediment over a broad region (up to several kilometers inland)(Umitsu et al., 1993

21、; Paris et al., 2007; Srinivasalu et al., 2007). Overthe last fifty years, the majority of previous studies related tosediment transport and scour focused on steady, uniform flowenvironments such as around riverbeds and

22、bridge piers. Recently,research has also begun on the study of sediment transport and scouraround coastal areas subject to wind-generated waves (e.g. Kraus andMarine Geology 269 (2010) 107–118DOI of original article: 10.

23、1016/j.margeo.2009.12.008.? Corresponding author.E-mail address: ylyoung@umich.edu (Y.L. Young).0025-3227/$ – see front matter © 2009 Elsevier B.V. All rights reserved.doi:10.1016/j.margeo.2009.12.009Contents lists

24、available at ScienceDirectMarine Geologyjournal homepage: www.elsevier.com/locate/margeohere on). Details of the experiment and results from other waveconditions will be presented in a separate report.3.2. Instrumentatio

25、nSixteen wave gauges were used to measure the wave profiles, ofwhich 12 were resistance-type wave gauges (WG, ImTech Inc.) andfour were ultrasonic wave gauges (DS, for distance sonic, Senix Corp.,TS-30S1-1V). The resista

26、nce-type wave gauges were deployedseaward of the shoreline from x=10 m to x=27 m and the ultrasonicwave gauges were installed landward of the shoreline, from x=28 mto x=32 m. The specific locations are shown in Fig. 2. E

27、ight pore-pressure sensors (PPS; Druck/GE, PDCR81) were installed near theshoreline at x=25 m and x=27 m respectively, with four verticallystacked in each location. The PPS were equally spaced vertically, with15 cm inter

28、vals, as shown in Fig. 2(b). Seven acoustic-Dopplervelocimeters (ADV, Nortek Vectrino+) were deployed from x=24 mto x=32 m to measure the near-bed fluid velocities. The ADVs werekept at approximately 3 cm above the bed b

29、y adjusting their verticalpositions in between the runs.Sediment flux measurements require the vertical variation of thesediment concentration and velocity. To deploy the necessary sensors,two wings were mounted on the b

30、ridge (shown in Fig. 4(a)), whichcould be moved along the guided tracks on the sidewalls of the basin.The wings were centered at x=23 m during all the waves for the 1:15slope bed configuration. Four ADVs were mounted on

31、one of thewings, and four optical backscatter sensors (OBS, D&A Instrument)were mounted on the other wing (see Fig. 5 for the layout of thesensors on the wings). A photograph of the experimental setup isshown in Fig.

32、 4(a). OBS sensors measure the sediment concentrationsin the fluid using optical back-scattering (Downing, 2006). The eightsensors were arranged so that the sampling volumes of the four ADVsand those of the four OBSs wer

33、e co-located. The wings were designedto have a slim foil-like geometry to minimize interferences with theFig. 1. The full wave basin where the experiment was conducted. Details of the 2D flume specifically built for this

34、 experiment (the lightly shaded area) are shown in Fig. 2.Fig. 2. Experimental setup: (a) plan view and (b) elevation view. This is a magnification of the lightly shaded flume area shown in Fig. 1. The setup of the wing

35、units (shadedrectangles) in this figure is detailed in Fig. 5. Notes on the flume coordinates system: The x axis is aligned with the cross-shore direction, with the positive direction pointinglandward and x=0 defined at

36、the neutral position of the wave maker. The z direction is aligned in the vertical direction and is positive pointing upward with z=0 defined at thebottom of the basin. The y axis is aligned with the longshore direction.

37、 The sensors are numbered sequentially with ascending (or, in a few cases, descending) x or z coordinate. Someof the names are shown while others can be easily interpolated.109 Y.L. Young et al. / Marine Geology 269 (201