台风作用下淤泥质海岸动力地貌响应  

Morphodynamic behavior of the mud coast in response to typhoon action

作　　者：戴志军[1] 张小玲[1] 闫虹[1] 李九发[1] 恽才兴[1] 

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《海洋工程》2009年第2期63-69,95,共8页The Ocean Engineering

基　　金：上海市科技启明星资助项目(06QA14016);国家海洋局908资助项目(HAD2);科技部河口海岸学国家重点实验室科研业务费资助(2008KYQN03)

摘　　要：基于200509号麦莎台风(近似百年一遇)作用前后杭州湾北岸龙泉-南竹港实测的海岸地形和水文资料,利用分形技术、冲刷深度和闭合水深等相关概念分析淤泥质海岸的剖面变化、岸线进退以及地形冲淤,进而探讨海岸响应台风作用的动力地貌行为。结果表明:1)台风作用前后的海岸动力地貌过程表现为水下类似沙坝的堆积体削平、凹处填洼,水下平台发育锯齿或较小的坝——槽,海岸剖面的分维数降低,剖面坡度处于平缓;2)麦莎台风对海床的整体冲淤幅度不大,这可能是由于研究区大潮讯的增水致使波浪对海床的塑造能力减弱以及码头的遮蔽作用造成;3)台风作用对海岸的冲刷深度约为0.8 m,闭合水深为9.5 m,近岸-1 m邻近区成为海岸响应台风作用最敏感的地带;泥沙主要在0 m到闭合水深区间的海床发生纵、横向运移。Based on the measured coastal topography and hydrological data of the northern coast of Hangzhou bay during the typhoon action, changes of coastal profiles, advance and recession of the shoreline and erosion and accretion of topography are analyzed to reveal morphody- namic behavior of Longquan-Nanzhu segment coast in response to typhoon action by fractal technique and conceptions of eroded depth and depth of closure. The results show that ： （ 1 ） Coastal morphodynamic processes during typhoon action could be described as that the crest of the sub- marine bar was cut down, the runnel was filled up and the submarine platform was eroded into several similar shapes of sawtooth or small bar- runnel. The fractal value of the whole profile was decreased and the grade of profile was mild. （2） The range of erosion and accretion for the whole seabed affected by the typhoon was small due to weak sculpture for the wave action resulting from increased water level in spring tide and the shelf of the dork. （3） The eroded depth was about 0.8 m and the depth of closure is 9.5m for the typhoon action. The nearshore zone at the depth of about - lm was sensitive to the typhoon and sediment transport occurring in the zone between 0 m and the depth of closure.

关 键 词：动力地貌 杭州湾北岸 形态响应 0509号麦莎台风 淤泥质海岸 

分 类 号：P737.11[天文地球—海洋地质]