The observations of seabed sediment erosion and resuspension processes in the Jiaozhou Bay in China

(整期优先)网络出版时间:2017-11-21
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Inestuarineandcoastalareas,theseabedisinaconstantprocessofdynamicchangeundermarineconditions.Seabedsedimenterosionandresuspensionareimportantprocessesthatsafelycontrolthegeologicalenvironment.FieldtripodobservationsconductedintheJiaozhouBayinChinaarereported,toinvestigatetheeffectsofhydrodynamicconditionsontheerosionandresuspensionprocessesoftheseabed.Theobservationalresultsshowthatthemaximumshearstresscreatedbytidalcurrentscanreach0.35N/m~2,whichishigherthanthewave-inducedshearstressduringfairweatherconditions.Aseabederosionfrequentlyoccursduringthefloodtide,whereasaseabeddepositionoccursduringebbtide.WavescanproduceabottomshearstressapproximatelyequivalenttothatinducedbycurrentswhenthelocalwindreachesForce4withaspeedof5m/s.Whenthewindreaches7m/sandthesignificantwaveheightreaches26cm,wavesplayamoresignificantrolethancurrentsinthedynamicprocessesoftheseabedsedimentresuspensionandleadtoahighvalueofturbiditythatisapproximatelytwotoeighttimeshigherthanthatinfairweather.Theseanalysesclearlyillustratethatperiodiccurrent-inducedsedimenterosionandresuspensionaredominantinfairweather,whereasepisodichighwavesareresponsibleforsignificantsedimentresuspension.AdditionalworkisneededtoestablishamorethoroughunderstandingofthemechanismsofsedimentdynamicsintheJiaozhouBay.