中强潮海滩剖面冲淤过程研究——以北海银滩为例  

Erosion and accretion of a meso-macro-tidal beach profile——A case from the Yintan Beach of Beihai

作　　者：黄祖明 戴志军[1] 黎树式 黄鹄 冯炳斌 HUANG Zuming;DAI Zhijun;LI Shushi;HUANG Hu;FENG Bingbin(State Key Lab of Estuarine and Coastal Research,East China Normal University,Shanghai 200062,China;The Key Laboratory of Coastal Science and Engineering,Beibu Gulf,Qinzhou 535011,China;Nanning Normal University,Nanning 530000,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]广西北部湾海岸科学与工程实验室,钦州535011 [3]南宁师范大学,南宁530000

出　　处：《海洋地质与第四纪地质》2021年第4期36-47,共12页Marine Geology & Quaternary Geology

基　　金：国家自然科学重点基金(41930537);国家自然科学基金(41666003,41866001)。

摘　　要：揭示中、强潮砂质海滩在波浪和潮汐作用下的剖面冲淤变化过程是理解海岸演变及沿海防护工程设计与旅游资源规划的核心内容。以北部湾北海银滩为例,基于GIS-RTK获取区域2014年7月—2018年2月逐月剖面高程实测数据,结合水文资料分析银滩剖面在外在驱动作用下的变化特征及冲淤机制。结果表明:①银滩内滨区域处于净侵蚀状态,低潮带及其以浅区破波带以弱淤积为主,冲流带展现持续、恒定净淤积特征。②一年中有263天波浪可引起银滩-3.41 m水深以浅的泥沙频繁扰动,由此造成内滨剖面快速变化,波高0.3~0.5 m的波浪引起的泥沙扰动水深控制冲流带、破波带和低潮带的淤积过程。③潮位波动导致波浪作用下海床泥沙活动的范围出现差异,由此引起海滩由陆向海出现"强淤积-弱淤积-弱侵蚀"特征。④造成区域较大增水的台风可大幅度提高各级别波浪扰动范围,对银滩整体剖面造成侵蚀。Changes in the erosional and depositional regime on a meso-macro tidal coast,under the actions of wave and tide,are significant for understanding coastal evolution,and making coastal engineering design and tourism resource development plan.In this study,the variation in beach profiles and associated driven factors are investigated,based on the hydrological data and measured monthly profile elevations,from July2014 to February 2018 on the Yintan beach of Beibu Gulf.The results can be summarized as follows:(1)The inshore area of the Yintan Beach remained in a state of net erosion,while the low-tide zone and its shallow surf zone were in weak siltation,and the swash zone in continuous and constant net siltation.(2)In a year there are 263 days,during which wave can make the sediment frequently disturbed in the shallow area less than 3.41 m,which can induce rapid changes in inshore zone,and the eddy water depths induced by the wave 0.3 m to 0.5 m in height control the depositional processes in the swash,surf and low-tide zones.(3)Fluctuation of tide level may cause the spatial differences in sediment movement on seabed and results in the distribution pattern of"strong siltation-weak siltation-weak erosion"from land to sea.(4)The typhoon may greatly cause storm surge elevation,increase the wave disturbance range,and bring about strong erosion of the whole beach.

关 键 词：海滩剖面 波浪扰动范围 冲淤过程 北海银滩 

分 类 号：P737.1[天文地球—海洋地质]