波流作用下砂泥复合型海滩砂泥转换带迁移研究  

Study on the migration of sand-mud transition on sandy-muddy beach under wave-current action

作　　者：祝潇 梁慧迪 陈维 时连强 ZHU Xiao;LIANG Huidi;CHEN Wei;SHI Lianqiang(College of Marine Engineering Equipment,Zhejiang Ocean University,Zhoushan 316022,China;Second Institute of Oceanography,MNR,Hangzhou 310012,China;Key Laboratory of Ocean Space Resource Management Technology,MNR,Hangzhou 310012,China)

机构地区：[1]浙江海洋大学海洋工程装备学院,浙江舟山316022 [2]自然资源部第二海洋研究所,浙江杭州310012 [3]自然资源部海洋空间资源管理技术重点实验室,浙江杭州310012

出　　处：《海洋工程》2024年第4期119-129,共11页The Ocean Engineering

基　　金：国家自然科学基金资助项目(41906151);浙江省自然科学基金资助项目(LY22E090011);自然资源部海洋空间资源管理技术重点实验室开放基金项目(KF-2021-106);浙江砂质海岸与淤泥质海岸生态修复关键技术研究项目(LHZ22D060001)。

摘　　要：为研究波流耦合作用下复合型海滩砂泥转换带(SMT)的迁移规律,建立了洞头区人工沙滩的多组分泥沙动力地貌概化模型,并采用工程后人工沙滩实测剖面冲淤数据进行了模型验证。通过对比不同水动力条件下沙滩地形变化及沉积物演变,分析了SMT迁移对各水动力条件的响应。模拟结果表明:人工沙滩在拦沙堤和岬角的掩护下滩面普遍呈淤积态势,湾内岸线稳定。然而由于拦沙堤波影区波浪动力削减,造成沙滩滩面泥化,SMT逐渐向岸移动,砂质滩面面积缩小约40%。SMT与潮汐、波浪关系密切,在潮波比值小于25时,SMT相对高程取决于潮汐和波浪的共同作用,与潮差呈正比、与波高呈反比。而在潮波比值大于25时,波浪作用几乎可以忽略,SMT高程取决于平均高潮位。此外,当波浪垂直于岸线时,沙滩泥化程度最低,SMT均匀分布在沙滩-潮滩交界面附近,随着水体含沙量(体积分数)的增加,波浪暴露区域SMT逐渐向岸迁移。In order to study the migration law of sand-mud transition(SMT)on sandy-muddy beach under wave-current activity,a generalized model of multi-component sediment dynamics for the artificial beaches in Dongtou area was established.The model was validated using measured profiles of erosion and deposition on the engineered artificial beaches.By comparing the changes in beach morphology and sediment evolution under different hydrodynamic conditions,the response of SMT migration to various hydrodynamic conditions was analyzed.The simulation results indicate that the artificial beaches generally exhibit a tendency of accretion under the protection of groins and headlands,with stable shoreline in the bay.However,due to the reduction of wave dynamic energy in the wave shadow area,the beach surface tends to become muddy,leading to the gradual landward migration of SMT and a reduction in sandy beach area by approximately 40%.The SMT is closely related to tides and waves,and when the ratio of tidal range to wave height is less than 25,the relative elevation of SMT depends on the combined action of tides and waves,positively correlated with tidal range and inversely proportional to wave height.When the ratio of tidal range to wave height exceeds 25,the wave action can be almost ignored,and the elevation of SMT depends on the mean highest tide level.Additionally,when waves are perpendicular to the shoreline,the degree of beach mudification is lowest,and SMT is evenly distributed near the beach-tidal interface.With the increase in sediment concentration in the water,the SMT gradually migrates landward in the exposed area of waves.

关 键 词：沙滩泥化 砂泥转换带 波流作用 砂泥复合型海滩 人工沙滩 

分 类 号：P753[交通运输工程—港口、海岸及近海工程]