北部湾防城港东湾白骨壤潮滩近底层动力响应台风作用的耗散过程  

Dissipation process of the near-bed hydrodynamics over Avicennia marina tidal flat in response to typhoon action

作　　者：黄祖明 戴志军[1] 周晓妍 龙楚琪 冯炳斌 罗杰骏 喜扬洋 HUANG Zuming;DAI Zhijun;ZHOU Xiaoyan;LONG Chuqi;FENG Bingbin;LUO Jiejun;XI Yangyang(State Key Lab of Estuarine&Coastal Research,East China Normal University,Shanghai 200062,China;Fourth Institute of Oceanography,Ministry of Natural Research,Beihai 536015,China;Guangxi Beibu Gulf Marine Research Center,Guangxi Academy of Sciences,Nanning 530007,China)

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 [2]自然资源部第四海洋研究所,广西北海536015 [3]广西科学院广西北部湾海洋研究中心,广西南宁530007

出　　处：《海洋工程》2023年第2期107-118,共12页The Ocean Engineering

基　　金：国家自然科学重点基金资助项目(41930537);广西重点研发计划项目(桂科AD19245158)。

摘　　要：揭示极端天气影响的红树林潮滩潮流能量耗散过程是理解生物海岸演变及滨海湿地生态修复工程的核心内容。以北部湾防城港东湾白骨壤红树林潮滩为例,基于声学多普勒流速仪(ADV)获取区域2020年8月连续6天的水动力和白骨壤红树林下垫面植被实测数据,分析白骨壤潮滩近底层动力响应台风“森拉克”的耗散过程。结果表明:1)正常天气涨、落潮期间,自光滩到白骨壤红树林林内近底层湍流动能变化具有潮汐不对称性特征。涨潮期间光滩—白骨壤红树林边缘、白骨壤红树林边缘—林内潮流挟沙能量分别通过泥沙沉降以及搬运泥沙两种方式沿程消耗,落潮期间潮流挟沙能量主要以泥沙净沉降的方式消耗。2)白骨壤通过其潮滩表层向上发育长约10 cm的呼吸根以降低湍流垂向紊动;红树林边缘的枝、叶通过影响水平方向上的水流动力,致使潮流挟沙能耗降低。3)与正常天气比较,台风“森拉克”期间东湾自光滩到白骨壤红树林林内近底层水体流速无明显变化,但流向偏转幅度明显变大。同时湍流动能的耗散率和用以搬运泥沙为主的潮流挟沙能耗亦均增大。The process of tidal current energy dissipation in mangroves over spring‐middle tidal coasts under extreme weather is one of the significant topics for understanding biological coasts evolution and coastal wetland restoration project.In this study,based on the measured hydrodynamic data by ADV and the underlying surface vegetation data of Avicennia marina for 6 consecutive days in August 2020,the hydrodynamical dissipation process of the tidal flat near the bottom of Dongwan's Avicennia marina in response to typhoon Sinlaku was analyzed.The results show that:1)During the flood and ebb tides,the changes of the turbulent kinetic energy from bared flat to Avicennia marina exhibited the characteristics of tidal asymmetry under the normal weather.Tidal current energy by carrying sediments from bared flat to Avicennia marina's edge and from Avicennia marina's edge to Avicennia marina's area was dissipated by transportation and settlement of sediment.And the energy of carrying sediment by tidal current during ebb tide was mainly consumed for net settlement in sediments.2)The Avicennia marina's pneumatophores of about 10 cm can attenuate the vertical turbulent kinetic energy,while the branches and leaves at the edge can reduce the tidal current energy consumption by attenuating the horizontal flow.3)Compared to those of the normal weather,there was no obvious change in the flow velocity near the bottom from bared flat to Avicennia marina during the period of typhoon Sinlaku,but the flow direction deflection was larger than that of the normal weather.Meanwhile,the dissipation rates of turbulent kinetic energy and sediment transport energy consumption were larger those in the normal weather.

关 键 词：近底层动力 湍流动能 潮流挟沙能耗 白骨壤 台风“森拉克” 

分 类 号：P753[交通运输工程—港口、海岸及近海工程]