摘要
入海河口由于径流的存在以及河口地貌形态的影响,存在涨、落潮水动力、悬沙以及盐度分布等不对称现象,同时这一不对称现象还存在显著的区域性和季节性差异。根据2013年7月和2014年1月洪、枯季长江口定点准同步水文泥沙调查结果,发现长江口分汊型河槽悬沙浓度在时间上存在洪枯季、大小潮不对称特征,在空间上存在东西向沿程分布、南北向横向分布以及垂向上表底层分布不对称特征。河势演变形成南、北支河口涨、落潮悬沙浓度不对称分布的整体格局;洪、枯季变化影响河口涨、落潮悬沙分布的再分配过程;大潮涨、落潮过程对悬沙分布不对称影响显著大于小潮;季节性风浪作用影响河口最大浑浊带涨、落潮悬沙不对称南北差异;底部高含沙浓度对口门段涨、落潮悬沙不对称性贡献显著。
Due to the influence of runoff and estuarine morphology, asymmetrical phenomena of hydrodynamics,suspended sediment concentration(SSC) and salinity occurs between the flooding and ebbing stage in the estuary.Such a phenomena also shows significant regional and seasonal differences. Based on hydrological survey in July2013 and January 2014 in the Changjiang River Estuary, it is found that suspended sediment concentration in the branched channels of the Changjiang River Estuary has asymmetric characteristics, which varies with flood and dry season as well as spring and neap tide. In terms of spatial variability, there exists along channel difference, interchannel difference as well as water colume difference. The evolution of the estuary controlls the overall SSC difference between the North Branch and South Branch. The flood and dry seasons affect the redistribution process of SSC in the estuary. Spring tides has a stronger impact on SSC asymmetry than that of neap tides. Theseasonal wave condition affect the SSC asymmetric distribution in the turbidity maximum zone of the estuary along the northsouth direction. The high sediment concentration near the bottom contributes significantly to the SSC asymmetry between flooding and ebbing stages at the river mouth.
作者
乔立新
张国安
何青
张卫国
李茂田
Qiao Lixin;Zhang Guoan;He Qing;Zhang Weiguo;Li Maotian(State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China)
出处
《海洋学报》
CAS
CSCD
北大核心
2020年第3期107-117,共11页
基金
国家自然科学基金(41671007)
国家重点研发计划(2017YFE0107400)
科技部基础性工作专项重点项目(2013FY112000)。
关键词
分汊型河口
河槽
悬沙浓度
涨、落潮不对称
季节性差异
branched estuary
channel
suspended sediment concentration
flood-ebb asymmetry
seasonal difference
