北海银滩响应台风作用的动力地貌过程  

Morphodynamic processes of the Yintan Beach in response to typhoon

作　　者：喜扬洋 王日明 冯炳斌 陈波[1] XI Yangyang;WANG Riming;FENG Bingbin;CHEN Bo(Guangxi Key Laboratory of Marine Environmental Science,Guangxi Beibu Gulf Marine Research Center,Guangxi Academy ofSciences,Nanning 530007,China;Key Laboratory of Coastal Science and Engineering/Qinzhou Key Laboratory for Eco-Restoration of Environment,Beibu GulfUniversity,Qinzhou 535011,China;Key Laboratory of Beibu Gulf Environmental Change and Resource Use,Ministry of Education,Nanning Normal University,Nanning 530000,China;State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200062,China)

机构地区：[1]广西科学院广西北部湾海洋研究中心,广西近海海洋环境科学重点实验室,广西南宁530007 [2]北部湾大学,广西北部湾海岸科学与工程实验室/钦州市环境生态修复重点实验室,广西钦州535011 [3]南宁师范大学,北部湾环境演变与资源利用教育部重点实验室,广西南宁530000 [4]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《热带海洋学报》2022年第4期97-104,共8页Journal of Tropical Oceanography

基　　金：国家自然科学基金重点项目(41930537);广西科学院基本科研业务费资助项目(2020YBJ704)。

摘　　要：极端高能事件影响下的海滩动力地貌过程直接关乎岸滩稳定及海堤安全。本文基于2020年16号台风“浪卡”前后北海银滩顺直岸段的剖面高程及表层沉积物等资料,探究了中等潮差的顺直响应台风作用的地貌变化机制。结果表明:1)台风后海滩地貌表现为冲流带的大型沙坝消失,后滨沙丘-滩槽体系被削平,滩面坡度趋于平缓。2)银滩沉积物均以中砂、细砂和极细砂为主,三者占比超过95%;台风后,高潮位带沉积物变细,低潮位带沉积物变粗,沙坝附近则出现粗细交错式变化;银滩中高潮位带滩面响应台风过程的特征与强潮型海滩相似,呈现消散型海滩的特征,而低潮位带滩面则因大型沙坝的作用而呈现弱潮型海滩特征。3)台风期间波浪是影响海滩的主要动力因素,海滩地形影响了近岸水动力的表现形式,从而改变了沉积物的粒径分布。The beach morphodynamic process under the influence of extreme high-energy events is directly related to coastal stability and seawalls safety.Based on the profile elevation and surface sediments of the Yintan Beach collected before and after the 202016th typhoon“Nangka”,this paper explores the mechanism of morphological changes of a meso-tidal beach in response to typhoon actions.The results show that:(1)In post-typhoon period,the beach morphological changes are manifested by the disappearance of a large sand bar and the flattening of the bar-trough system,leading to a more gentle beach slope;(2)Sediment in Yintan Beach is mainly medium sand,fine sand and very fine sand,which account for more than 95%;The sediment grains become finer in the high tide zone and coarser in the low tide zone,while both increase and decrease in sediment grain size can occur near the sand bar;The morphodynamic process of mid-to-high tide zone of the Yintan Beach in response to a typhoon is similar to that of a macro-tidal beach,which is characterized by dissipative condition.However,the morphodynamic process of low tide zone of the Yintan Beach behaves like a micro-tidal beach due to the existence of a large sand bar;(3)During the typhoon,wave is the main dynamic factor affecting the beach,and the topography affects the manifestation of nearshore hydrodynamics,thereby changing the grain size distribution of sediment.

关 键 词：北海银滩 动力地貌过程 台风“浪卡” 海滩侵蚀 沙坝 

分 类 号：P737.13[天文地球—海洋地质]