简介：—Inthispaper,anonlinearmodelispresentedtodescribewavetransformationinshallowwat-erwiththezero-vorticityequationofwave-numbervectorandenergyconservationequation.Thenonlineareffectduetoanempiricaldispersionrelation(byHedges)iscomparedwiththatofDalrymple＇sdispersionrelation.Themodelistestedagainstthelaboratorymeasurementsforthecaseofasubmergedellipticalshoalonaslopebeach,wherebothrefractionanddiffractionaresignificant.Thecomputationre-sults,comparedwiththoseobtainedthroughlineardispersionrelation.showthatthenonlineareffectofwavetransformationinshallowwaterisimportant.Andtheempiricaldispersionrelationissuitableforre-searchingthenonlinearityofwaveinshallowwater.

简介：Basedonthehydrodynamicalfeatureandthetheoreticalvelocityprofilesoftidalflowandwind-inducedflowinshal-lowsea,acomputationalmodelisestablishedforthefirsttime,whichcanseparateobservedvelocityintotidalvelocityandwind-inducedvelocitybyuseoftheleastsquaremethod.Withthemodel,notonlythesurfacevelocitiesoftidalflowandwind-inducedflowareobtained,butalsothebedroughnessheightisdeterminedandthewindvelocityabovethewa-tersurfaceisestimated.Forverificationofthemodel,theobservedvelocityintheYellowRiverEstuaryandthelaborato-rytestisseparated,thenitisappliedtotheYangtzeRiverEstuary.Alltheresultsaresatisfactory.Theresearchresultsshowthatthemodelissimpleinmethod,feasibleinprocessandreasonableinresult.Themodelisavalidapproachtoanalysisandcomputationoffielddata,andcanbeappliedtoseparatetheobservedvelocityinshallowsea;atthesametime,reasonableboundaryconditionsofthesurfaceandbottomcanbeobtainedfortwo-andthree-dimensionalnumericalsimulation.

简介：Athree-dimensionalnumericalmodel,EFDC(environmentalfluiddynamicscode)isappliedtothePamlicoRiverEstuary(PRE)ineasternNorthCarolinaoftheUnitedStatestoexaminethewindimpactonpollutantagedistributionsandresidencetime.Aseriesofmodelexperimentsrepresentingbasecase,remote-wind-inducedwaterlevelset-upandlocalwindscasesareconducted.ModelresultsindicatethatthepollutantmeanageandthesystemresidencetimearefunctionsofgravitationalcirculationinthePRE.Thesystemresponsestoremote-wind-inducedwaterlevelset-uparedifferentindifferentportionsofthePRE.Undersuchcondition,dissolvedsubstancesintheupstreamportionofthePREhaveayoungerageandshorterresidencetime(comparedwiththebasecase),bycontrast,theyhaveaolderageandlongerresidencetimeinthedownstreamportionofthePRE.Upriveranddownriverlocalwindsappeartohaveoppositeimpactsonpollutantagedistributions.ThesubstancesareretainedmuchlongerwithinthePREunderupriverwindthanthoseunderdownriverwind.Themodelresultsalsosuggestthatacross-riverwindsmayleadtolongerresidencetimethroughenhancedturbulencemixing,whichslowsdownthegravitationalcirculationinthePRE.

简介：Basedonthe1stordercnoidalwavetheory,thewavediffractionaroundthepiergroupinshallowwaterisstudiedinthispaper.Theformulasforcalculatingthenonlinearwaveforcesarealsopresentedhere.Inordertoverifythetheoreticalresults,modeltestsareconductedinthewaveflumeinTheStateKeyLaboratoryofCoastalandOffshoreEngineeringlocatedinDalianUniversityofTechnology.TherangeofthewaveparametersintheexperimentsischaracteristicwaveperiodTg/d1/2=8.08-22.86,characteristicwaveheightH/d=0.10.45.Theresultsobtainedfromtheexperimentsagreewiththetheoreticalresultsquitewell.Itisshownthat,inshallowwaterthenonlinearwaveforcesactingonapiergrouparegreaterthanthosecalculatedbylinearwavetheory,thevalueofincrementinwaveforceincreaseswiththeincreasesofthenonlinearityofthewave.Inthewaverangestudiedinthispaper,thenonlinearwaveforcecanreachover4timestheforcecalculatecdbylinearwavetheory.Thus,itissuggestedthat,whenTg/d1/2>8,thewaveforceonthepiersinthepiergroupinshallowwatershouldbecalculatedbyusingthecnoidalwavetheory.

简介：Basedonthe1stordercnoidalwavetheory,thenonlinearwavediffractionaroundacircularcylinderinshallowwaterisstudiedinthispaper.Theequationofthewavesurfacearoundthecylinderisformulatedandbyusingthisformulathewavesurfaceelevationonthecylindersurfacecanbeobtained.Inthispaper,theformulaforcalculatingthecnoidalwaveforceonacircularcylinderisalsoderived.Forthewaveconditionswhichareoftenencounteredinpracticalengineeringdesigns,theratiosofthenonlinearwaveforcestothelinearwaveforcesarecalculated,andtheresultsareplottedinthispaperfordesignpurposes.Inordertoverifythetheoreticalresults,modeltestsareconducted.Aftercomparingthetestresultswiththetheoreticalones,itisconcludedthat,inshallowwater,forthecaseofTg/d1/2>8-10andH/d>0.3,thecnoidalwavetheoryshouldbeusedtocalculatethewaveactiononacylindricalpier.

简介：Tostudythecompactionlawandoverpressureevolutionindeepwatershallowsediments,alarge-straincompactionmodelthatconsidersmaterialnonlinearityandmovingboundaryisformulated.Themodelconsidersthedependenceofpermeabilityandmaterialpropertiesonvoidratio.ThemodifiedCam-Claymodelisselectedastheconstitutiverelationsofthesediments,andthedeactivation/reactivationmethodisusedtocapturethemovingtopsurfaceduringthedepositionprocess.Aone-dimensionalmodelisusedtostudythecompactionlawoftheshallowsediments.Resultsshowthatthesettlementoftheshallowsedimentsislargeundertheirownweightduringcompaction.Thevoidratiodecreasesstrictlywithburialdepthanddecreasesmorequicklyneartheseafloorthaninthedeeperlayers.Thegenerationofabnormalpressureintheshallowflowsandsiscloselyrelatedtothecompactionlawofshallowsediments.Thetwomainfactorsthataffectthegenerationofoverpressureinthesandsaredepositionrateandpermeabilityofoverlyingclaysediments.Overpressureincreaseswithanincreaseindepositionrateandadecreaseinthepermeabilityoftheoverlyingclaysediment.Moreover,anupperlimitfortheoverpressureexists.Atwo-dimensionalmodelisusedtostudythedifferentialcompactionoftheshallowsediments.Theporepressurewillstillincreaseduetotheinflowoftheporefluidfromtheneighboringclaysedimenteventhoughthedepositionprocessisinterrupted.

简介：Physicalpropertiesofseawater,suchassalinity,temperature,densityandacousticvelocity,couldbedemarcatedthroughdegradationofenergycausedbywaterabsorption,attenuationandotherfactors.Toovercomethechallengingdifficultiesinthequickmonitoringofthesephysicalproperties,wehaveexploredthehighresolutionmarineseismicsurveytoinstantlycharacterizethem.Basedontheuniquewavefieldpropagatingintheseawater,wehavedevelopedanewapproachtosuppressthenoisecausedbytheshallowseawaterdisturbanceandobtainusefulinformationforestimatingtheseawaterstructure.Thisapproachimprovesseismicdatawithhighsignal-to-noiseratioandresolution.Theseismicreflectionimagingcanmaptheseawaterstructureacoustically.Combinedwiththeknowledgeoflocalwaterbodystructureprofileoveryears,theinstantmodelforpredictingtheseawaterpropertiescouldbebuiltusingtheseismicdataacquiredfromthespeciallydesignedhighprecisionmarineseismicacquisition.Thismodelcanalsobeupdatedwithinstantobservationandthecompletedataprocessingsystem.Thepresentstudyhasthepotentialvaluetomanyapplications,suchas3Dseawatermonitoring,engineeringevaluation,geologicaldisasterassessmentandenvironmentalassessment.

简介：Thetidalasymmetry-inducedsiltationbelowtidalbarriersisaworldwideproblemthatrestrictsregionalsocio-economicandenvironmentaldevelopment.Thehydrodynamicprocessesofthesmallmudestuaryalsofeatureahighuncertaintyafterestuaryrestorationmeasures.Inthisstudy,ahydrodynamicmodelbasedontheMIKE21isusedtoquantifytheresponsesoftidalasymmetrytoatwo-phaserestorationprojectinShuanglongEstuary,BohaiBay,China.Accordingtothenumericalmodelingresults,thetidalflatremovalintheupperestuary(first-phaserestoration)inducesthefloodasymmetryswitchingtotheebbasymmetryinunrestoredreachbutenhancesfloodasymmetryinwideningrestoredreach.Althoughthetidalasymmetryrevertstoflood-dominatedpatternafterfullrestorationovertheestuary,theimbalancebetweenfloodandebbvelocitiesisrelieved.Apossiblenetsedimenttransportpatternbasedonacomparisonofdominantasymmetriccurrentandactualsedimenttransportperiodshowsnetsedimentsintheupperestuaryandinlettransportseawardandlandward,respectively,inthefirst-phaserestoration,whereaslandwardnetsedimenttransportoccursinthewholeestuaryunderthesecond-phaserestorationscenario.Giventheseresults,weassumethataswitchfromtheflood-dominatedestuarytoebb-dominatedestuarycanbecausedbyredesigningthecross-sectionalprofile.ThequantitativecomparisonofLagrangianresidualcurrentsalsoimpliesthatachannel–shoalstructureratherthanaflatbathymetrycanpromotethemasstransport.Therefore,reshapingthechannel–tidalflatsysteminrestorationprojectscanpreventthesedimentationoftheestuaryandimprovethewaterenvironment.

简介：Asoneofthekeysafetyproblems,themotionperformanceandtouchingseabottomofaFPSOarepaidmuchattentionbytheoceanoilcompanieswhentheFPSOisexposedtosurvivalstormsintheshallow-waterworkingareas.Inthispaper,timedomainnumericalsimulationsarecarriedoutona160kDWTFPSOwithaYokemootingsystemmooredintheBZ25-1oilfieldwithawaterdepthof16.7m.Theresultsarecomparedwiththoseofthecorrespondingmodeltests.Goodagreementshowsthatthetime-domainsimulationscanbeusedtopredicttheperformanceoftheFPSOinshallow-waterreasonably.ItisfoundthatthetouchofseabedbyafullyloadedFPSOoccurredfewtimesundersurvivalstormconditions.Therefore,theFPSOshouldbelessloadedthanthatinthefullyloadedconditionunderthesurvivalstorms.

简介：潮汐的流动是一个周期的运动不稳定、不一致，它显然有加速和减速过程，特别在沿海的浅水里。潮汐的流动雷纳兹应力的垂直分发从线性分发背离了的许多研究表演。潮汐的流动雷纳兹压力的寓言的分发被歌等建议。(2009)。尽管模型更好充满领域观察和室内的试验性的数据，它有潮汐的流动雷纳兹应力的更低的截断的系列扩大，并且对分发的描述不是很全面的。由介绍潮汐的流动的运动方程并且改善，寓言的分发由歌等建立了。(2009)，潮汐的流动雷纳兹压力的立方的分发被建议。立方的分发被领域数据验证很好(Bowden和Fairbairn，1952；Bowden等，1959；Rippeth等，2002)并且试验性的数据(Anwar和阿特金斯，1980)，与Kuo等的数字模型结果一致。(1996)，并且与潮汐的流动雷纳兹压力的寓言的分发相比。这立方的分布比寓言的分发，而且罐头不仅好，这更好被显示出反映与潮汐的流动减速与潮汐的流动加速并且向上向下从线性分发背离的雷纳兹应力的基本特征，为潮汐的流动的速度侧面上的进一步的学习的基础。

简介：Deepwatersedimentsarepronetolosscirculationindrillingduetoalowoverburdengradient.Howtopredictthemagnitudeofleak-offpressuremoreaccuratelyisanimportantissueintheprotectionofdrillingsafetyandthereductionofdrillingcostindeepwater.Startingfromthemechanicalpropertiesofashallowformationandbasedonthebasictheoryofrock-soilmechanics,thestressdistributionaroundaboreholewasanalyzed.Itwasfoundthattherockorsoilonaboreholeisintheplasticyieldstatebeforetheeffectivetensilestressisgenerated,andtheeffectivetangentialandverticalstressesincreaseasthedrillingfluiddensityincreases;thus,tensilefailurewillnotoccurontheboreholewall.Basedontheresultsofstresscalculation,twomechanismsandleak-offpressurepredictionmodelsforshallowsedimentsindeepwaterdrillingwereputforward,andthecalculatedvaluesofthesemodelswerecomparedwiththemeasuredvalueofshallowleak-offpressureinactualdrilling.TheresultsshowthattheMHPS(minimumhorizontalprinciplestress)modelandtheFIF(fracturinginformation)modelcanpredictthelowerandupperlimitsofleak-offpressure.ThePLC(permeablelostcirculation)modelcancomprehensivelyanalyzethefactorsinfluencingpermeableleakageandprovideatheoreticalbasisforleak-offpreventionandpluggingindeepwaterdrilling.

简介：MuchattentionshouldbepaidtoalargeFPSOmooredpermanentlyinanoilfieldwithwaterdepthofonlyabout20m,sinceshallowwatereffectsonthehydrodynamicsmaybringaboutcollisionanddamage.A160kDWTFPSOwithapermanentsoftyokemooringsystemisinvestigatedwithvariousshallowwaterdepthsandfocusesarethelowfrequencysurgemotionandmooringload.ComputationfortheFPSOsystemismadebasedonlinear3-Dpotentialfluidtheoryandtime-domainnumericalsimulationmethod.CorrespondingmodeltestiscarriedoutintheoceanengineeringbasinofShanghaiJiaoTongUniversity.Itisshownthat,inthesurgenaturalperiod,lowfrequencysurgemotionandmooringforceincreaseremarkablywiththedecreaseofwaterdepth.Especially,thesmallertheratioofwaterdepthanddraughtis,thequickertheincreaseis.Theshallowwatereffectsshouldbetakenintoaccountcarefullyfordeterminingthedesignloadofasinglepointmooringsystem.

简介：Shallowwaterflow（SWF）,adisastrousgeohazardinthecontinentalmargin,hasthreateneddeepwaterdrillingoperations.Underoverpressureconditions,continualflowdeliveringunconsolidatedsandsupwardintheshallowlayerbelowtheseafloormaycauselargeandlong-lastinguncontrolledflows;theseflowsmayleadtocontrolproblemsandcausewelldamageandfoundationfailure.Eruptionsfromover-pressuredsandsmayresultinseafloorcraters,mounds,andcracks.Detailedstudiesof2D/3DseismicdatafromaslopebasinoftheSouthChinaSea（SCS）indicatedthepotentialpresenceofSWF.Itiscommonlycharacterizedbylowerelasticimpedance,ahigherVp/Vsratio,andahigherPoisson＇sratiothanthatforthesurroundingsediments.AnalysisofgeologicaldataindicatedtheSWFzoneoriginatedfromadeepwaterchannelsystemwithgasbearingover-pressuredfluidflowandahighsedimentationrate.WeproposedafluidflowmodelforSWFthatclearlyidentifiesitsstressandpressurechanges.TheruptureofpreviousSWFzonescausedthefluidflowthatoccurredintheBaiyunSagofthenorthernSCS.

简介：在华南海(SCS)的浅南方的翻发行量(MOC)的低频率的可变性为19002010的时期用一个简单海洋数据吸收(苏打)产品被调查。一个动态分解方法在MOC在哪个被分解成Ekman被使用，外部模式，并且垂直砍部件。结果证明所有三个动态部件在SCS贡献季节、年度的吝啬的浅MOC的形成。在SCS的浅MOC由二个房间组成：一顺时针方向在南方的房间和在北方的一个逆时针方向的房间；前者被Ekman流动控制，后者被外部barotropic流动统治，与贡献垂直砍是减少两个房间的大小。另外，在南方的MOC的力量被发现在过去的世纪有一个掉落的趋势，主要对一变弱减少外部部件的运输的吕宋岛海峡运输(LST)到期。进一步的分析建议变弱LST是仔细与一在赤道的太平洋上变弱西的风异例有关，它导致向北赤道的水流(NEC)分叉并且这样的向南方的移动吕宋岛的自台湾东面的菲律宾海流向日本的暖流东方的更强壮的运输。

简介：Inthisstudy,wesimulatedtyphoonwavesintheshallowwatersaroundtheZhoushanIslandsusingtheWaveWatch-III(WW3)modelversion5.16,thelatestversionreleasedbytheNationalOceanicandAtmosphericAdministration.Specifically,weusedin-situmeasurementstoevaluatetheperformanceofsevenpackagesofinput/dissipationsourcetermsintheWW3model.WeforcedtheWW3modelbywindfieldsderivedfromacombinationoftheparametricHollandmodelandhigh-resolutionEuropeanCenterforMedium-RangeWeatherForecasts(ECMWF)winddataina0.125°grid,hereincalledH-Ewinds.WetrainedtheH-EwindsbyfittingashapeparameterBtobuoy-measuredobservations,whichresultedinasmallestrootmeansquareerror(RMSE)of3ms?1forB,whentreatedasaconstant0.4.Then,weappliedtheseveninput/dissipationtermsofWW3,labelledST1,ST2,ST2+STAB2,ST3,ST3+STAB3,ST4,andST6,tosimulatethesignificantwaveheight(SWH)upto5mduringtyphoonsFungwongandChan-homaroundtheZhoushanIslands.WethencomparedtheSWHsofthesimulatedwaveswiththosemeasuredbythein-situbuoys.TheresultsindicatethatthesimulationusingST2performsbestwithanRMSEof0.79mfortyphoonFung-wongandanRMSEof1.12mfortyphoonChan-hom.Interestingly,wefoundthesimulatedSWHresultstoberelativelyhigherthanthoseoftheobservationsintheareabetweenHangzhouBayandtheZhoushanIslands.Thisbehaviorisworthyoffurtherinvestigationinthefuture.

简介：Thestabilityofsubmarinegeologicalstructureshasacrucialinfluenceontheconstructionofoffshoreengineeringprojectsandtheexploitationofseabedresources.Marinegeologistsshouldpossessadetailedunderstandingofcommonsubmarinegeologicalhazards.Currentmarineseismicexplorationmethodsarebasedonthemosteffectivedetectiontechnologies.Therefore,currentresearchfocusesonimprovingtheresolutionandprecisionofshallowstratumstructuredetectionmethods.Inthisarticle,thefeasibilityofshallowseismicstructureimagingisassessedbybuildingacomplexmodel,anddifferencesbetweentheseismicinterferometryimagingmethodandthetraditionalimagingmethodarediscussed.Theimagingeffectofthemodelisbetterforshallowlayersthanfordeeplayersbecausecoherentnoiseproducedbythismethodcanresultinanunsatisfactoryimagingeffectfordeeplayers.Theseismicinterferencemethodhascertainadvantagesforgeologicalstructuralimagingofshallowsubmarinestrata,whichindicatescontinuoushorizontalevents,ahighresolution,aclearfault,andanobviousstructureboundary.TheeffectsoftheactualdataappliedtotheShenhuareacanfullyillustratetheadvantagesofthemethod.Thus,thismethodhasthepotentialtoprovidenewinsightsforshallowsubmarinestrataimaginginthearea.

简介：小规模的bedforms的词法特征在Dafeng潮汐的公寓上借助于声学的介绍声纳被测量，江苏在2009，并且在Jiulong河口，厦门在2010，分别地。多阀值价值方法被利用揭示bedforms是在场的词法沿着波动。获得的数据集的分析显示出那：(1)沙涟漪能有不规则的形状，并且(2)在bedform形态学的变化在一个单个潮汐的周期以内是小的，但是可能在几个潮汐的周期上重要。分数维图形和海床粗糙的variogram分析揭示了在当前的速度和海床粗糙的分数维的尺寸之间的一种重要关系的存在。作为当前的速度增加，有小规模的底部结构的一个趋势的海床粗糙增加被大规模结构正在代替。而且，大规模底部结构的表面也能由于小规模的特征的缺席变得光滑或由于附加小规模的结构的存在变得更不平。

简介：Inrecentyears,infrastructureconstructiononcoralreefshasbeenincreasinglydeveloped.Therefore,theshallowstratastabilityofcoralreefsintheSouthChinaSeashouldbeevaluated.ThisstudyaimstoinvestigatetheprofilesfortheshallowstrataofcoralreefsinthesouthwestoftheYongshuReef,particularlyinthehydrodynamicmarineenvironment,andtoestablishageologicalmodelfornumericalsimulationusingGeo-Studio.Theshallowstrataofthecoralreefsincludemassgravel,sandgravel,mid-coarsesand,siltysand,finesand,andreeflimestone.Theshallowreefslopenearthelagoonissimilartoa‘layercake＇,inwhichthesideclosetotheseaisanalogoustoa‘blockcake＇.Thesimulationresultsshowedthatcoralreefstabilitydependsonwaveloadsandearthquakestrengthandonthephysicalpropertiesofcoralreefs.Thefactorofsafetyfortheouterreefisgreaterthan10.0understatic,wave,andseismicconditions;thisindicatedthattheouterreefswerelessaffectedbywavesandearthquakes.However,thefactorofsafetynexttothelagoonvariedfrom0.1to5.3.Thevariationwasprimarilycausedbythethickstrataofcoralreefsclosetothesea（reeflimestone,typicallywiththethickness〉10mandequivalenttoablock）.Thesoilandrocklayersinthecoralreefstratawiththicknesses〈10mshowedweakengineeringgeologicalcharacteristics.Ourfindingscanprovideusefulinformationtofutureconstructionprojectsoncoralreefs.

简介：这份报纸基于海浪折射和浅水的波浪理论用单个框架的好决定的光遥感形象论述一个深测术倒置方法。首先，在浅水里的水深度，波长和波浪弧度频率之中的关系基于浅水的波浪理论被推出。就在光遥感形象的复杂波浪分发而言，快Fourier变换(快速傅里叶变换)和空间侧面大小被申请测量波长。然后，波浪弧度频率被在波长分析长途的变化计算，它在在一幅单个框架的图象获得波浪弧度频率解决了一个关键问题。案例研究为海南岛的Sanya海湾被进行，中国。从QuickBird卫星的单个框架的好决定的光遥感形象被用来转换没有外部输入参数的深测术。数字举起模型(DEM)的结果与1:25的规模与一份海图表被作比较000。转换深测术的root-mean-square错误是1.07m，并且相对错误是16.2%。因此，建议方法为真深度和环境参数包括没有要求有优点，并且为印射浅沿海的水的深测术是可行的。

简介：