周良勇, 陈斌, 刘健, 胡刚, 梁源. 江苏废黄河口外夏季悬浮泥沙运动[J]. 海洋地质与第四纪地质, 2009, 29(6): 17-24. DOI: 10.3724/SP.J.1140.2009.06017
引用本文: 周良勇, 陈斌, 刘健, 胡刚, 梁源. 江苏废黄河口外夏季悬浮泥沙运动[J]. 海洋地质与第四纪地质, 2009, 29(6): 17-24. DOI: 10.3724/SP.J.1140.2009.06017
ZHOU Liangyong, CHEN Bin, LIU Jian, HU Gang, LIANG Yuan. OBSERVATION OF CURRENTS AND SUSPENDED SEDIMENT CONCENTRATION OFF NORTHERN JIANGSU COAST, CHINA[J]. Marine Geology & Quaternary Geology, 2009, 29(6): 17-24. DOI: 10.3724/SP.J.1140.2009.06017
Citation: ZHOU Liangyong, CHEN Bin, LIU Jian, HU Gang, LIANG Yuan. OBSERVATION OF CURRENTS AND SUSPENDED SEDIMENT CONCENTRATION OFF NORTHERN JIANGSU COAST, CHINA[J]. Marine Geology & Quaternary Geology, 2009, 29(6): 17-24. DOI: 10.3724/SP.J.1140.2009.06017

江苏废黄河口外夏季悬浮泥沙运动

OBSERVATION OF CURRENTS AND SUSPENDED SEDIMENT CONCENTRATION OFF NORTHERN JIANGSU COAST, CHINA

  • 摘要: 利用对江苏北部废黄河口水下斜坡和平坦海床上同步声学多普勒测流仪(ADP)测流和悬浮体取样数据,分析了本区近海水动力条件和泥沙运移。三站的同步调查显示,本海区潮周期悬沙净通量方向以南向为主,净通量在103~104kg/m之间。依据三站同步资料,初步估算穿过本区的泥沙通量接近长期侵蚀输沙的平均值。潮周期内悬浮泥沙含量呈周期性变化,靠近岸边浅水区的悬浮泥沙含量变化尤其明显。流速数据和悬浮体含量数据对比显示,底层流速与悬浮体含量的关系密切。这说明悬浮体含量变化与海底沉积物的再悬浮有关。悬沙含量峰值出现在急流后,ADP测流垂向断面数据显示急流时,流速梯度高,因而,急流时有较大的剪切速度,使沉积物受到侵蚀或再悬浮,从而使悬沙含量在急流后达到峰值。

     

    Abstract: The abandoned Yellow River delta off Jiangsu coast is an important sediment source area, where erosion occurs and large amounts of suspended materials are carried seaward. In order to understand the hydrodynamic process here, a 3-vessel simultaneous measurement was conducted with ADP (acoustic Doppler profiler) and water samplers in autumn of 2006. The analyses of survey data show suspended sediment fluxes, the changes of currents and suspended sediment concentrations. The net suspended sediment fluxes of a tidal cycle range from 103 kg m-1 to 104kg m-1, mainly to the south. First order estimation of yearly fluxes through the area is similar to a long-term average estimation. The investigation shows the currents are controlled by tides. The suspended sediment concentrations change within a tidal cycle. There are peaks of suspended sediments concentrations corresponding approximately to the time just after the maximum current velocity. Data show that velocity gradients become larger when velocity is bigger. High velocity gradients mean high bed shear stress. The high bed shear stress in turn causes the erosion and resuspension of seabed sediments, resulting in a high suspended sediment concentration in the water column.

     

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