台风作用下的港湾型潮滩沉积过程 以2008年“凤凰”台风对福建省罗源湾的影响为例  

Effects of typhoon on sedimentary processes of embayment tidal flatA case study from the "Fenghuang" typhoon in 2008

作　　者：王爱军[1] 叶翔[1] 陈坚[1] 

机构地区：[1]国家海洋局第三海洋研究所海洋与海岸地质环境开放实验室,福建厦门361005

出　　处：《海洋学报》2009年第6期77-86,共10页

基　　金：国家自然科学基金资助项目(40606012);福建省"九O八"专项资助项目(908-01-FJ-III)

摘　　要：通过对＂凤凰＂台风的现场观测和沉积物样品的分析,结果表明,在台风影响下潮水淹没时间增长,增水达1.1 m;台风期间互花米草盐沼内流速变化较复杂,而且盐沼内部流速大于盐沼边缘的;台风期间盐沼边缘潮周期平均悬沙含量是台风前2 d的7倍;台风期间十分之一波高最大为1.54 m。滩面重复测量结果显示,台风登陆期间整个光滩滩面都发生了侵蚀,盐沼内部有部分地区发生侵蚀,侵蚀深度为4.55.5 cm,盐沼边缘的侵蚀深度仅为0.7 cm,侵蚀原因主要是植被在风浪作用下从根部折断,从而带走了滩面的沉积物;随着台风强度的减弱,整个滩面均接受悬沙沉降;台风带来的强降雨是影响滩面沉积物活动的重要因素。Typhoon,as a high energy dynamic event,has the obvious influence on the sedimentary processes of the tidal flat.The Luoyuan Bay is located in the north of Fujian Province,China and the intertidal flat is distributed extensively in the bay.In order to understand the sedimentary processes of the tidal flat during this typhoon event,the in situ measurements of the water level,the tidal current speed,the suspended sediment content（SSC） and the wave height were carried out on the tidal flat during the period when the ＂Fenghuang＂ typhoon influenced the region,and the surfacial sediments.under the different conditions were collected.Analyzing the obtained data shows that the water inundation time increases,and the value of storm surge can reach 1.1 m;the variations of water current flow are very complicated,and the current velocity in the inner of Spartina alterniflora marsh is higher than that at the marsh edge.The influence of the typhoon on the SSC was highly significant,with the average SSC over the whole tide cycle being 7 times 2 d before the tyhhoo occurred.The decimus wave height can reach 1.76 m with the maximum water depth of 4 m.The repeated surveys of surface elevation show that the erosion occures on the whole bare flat along the section;only certain regions within the inner of marsh are eroded,with the erosion depth of 4.5～5.5 cm,however,the value only reaches 0.7 cm at marsh edge.The main reason of erosion on the marsh is that the plant roots are snapped off on the flat surface under the interactions among wind,wave and current,which carry off the sediment around the plant roots.With the decreasing of influencing intensity of the typhoon event,the whole flat experienced deposition.The rainfall intensity plays an important role on sediment activity.

关 键 词：台风 港湾型潮滩 沉积过程 互花米草盐沼 侵蚀 淤积 福建省罗源湾 

分 类 号：P736.21[天文地球—海洋地质] P731.23[天文地球—海洋科学]