摘要
利用黄河干流大型水库进行调水调沙,在短期内将大量沉积物快速输送入海,是河口泥沙异重流触发的重要窗口期。根据2010年调水调沙期间黄河口沉积动力现场观测资料,建立覆盖整个渤海海域的ROMS数学模型,以黄河利津站逐日水沙数据和海域潮汐、风场数据作为模型驱动条件,模拟调水调沙期间的河口泥沙异重流发育过程。模拟结果显示,在没有大风扰动的情况下,河流入海悬沙浓度>29.0 kg/m3时会在河口产生高密度泥沙异重流。黄河冲淡水携带大量悬浮物从河口流出后,与海水迅速混合,在潮流影响下,冲淡水舌随时间由西北向东南偏转,输运至莱州湾西侧。淡水和沉积物主要以表层羽状流和底层异重流形式输运:表层羽状流扩展范围较大,输运路径为河口西北方向-远岸(河口东北区域)-莱州湾西侧;底层异重流扩散范围较小,输运路径为河口西北方向-河口沿岸(东)-莱州湾西侧。河口泥沙异重流生消和水体垂向结构存在周期性变化特征:落潮时段异重流发育较好,水体层化增强;涨潮时段异重流逐渐消亡,水体混合增强。估算出黄河口清水沟清8叉流路主泓区内水体由河口径流、潮汐应变和潮汐搅动引起的势能变化率,其中潮汐应变和潮汐搅动起主导作用,比河口径流引起的势能变化率高出2~3个数量级(102~103)。
Using large reservoirs on the mainstream of the Yellow River to adjust water and sediment, or socalled water and sediment regulation, will transport a huge amount of sediment into the sea in a very short time. It is an important window period to trigger the hyperpycnal flow in the estuary. This paper is devoted to the forming process of the estuarine hyperpycnal flow with daily water and sediment data from the Lijin station and the tide and wind field data from the sea in addition to laboratory simulations. The research has reached following conclusions. The hyperpycnal flow will be formed when the suspended sediment concentration of the runoff input exceeds 29.0 kg/m3. Under the influence of the tidal current, the moving direction of the diluted water tongue shifts from northwest to southeast over time, and ends on the west side of Laizhou Bay. The surface plume has a wider influence range, and the transportation path goes from the northwest of the estuary-remote bank(northeast area of the estuary) up to the west side of Laizhou Bay with less suspended matter carried and the suspended matter can hardly be transported to Laizhou Bay. The bottom hyperpycnal flow moves from the northwest of the estuary to the west along the estuary(east) with a small amount of suspended solids reached at the Laizhou Bay.Factors influencing the water structure mainly include runoff injection, tidal strain and stirring, among which the tidal strain and stirring is 2~3 order in magnitude(102~103) higher than the runoff injection.
作者
李庆余
王爱美
吴晓
涂德耀
王厚杰
LI Qingyu;WANG Aimei;WU Xiao;TU Deyao;WANG Houjie(Collcge of Marinc Gcosciences,Ocean University of China.Qingdao 266100,China;Key Laboratory of Submarine Gcosciences and Prospecting Techniques,Ministry of Education,Qingdao 266100,China)
出处
《海洋地质前沿》
CSCD
北大核心
2021年第8期52-63,共12页
Marine Geology Frontiers
基金
国家杰出青年科学基金“现代黄河入海沉积物从源到汇的关键沉积动力过程”(41525021)。
关键词
黄河口
河口泥沙异重流
ROMS数值模拟
混合与层化
调水调沙
Yellow River Estuary
estuarine hyperpycnal flow
numerical model
mixing and stratification
water and sediment regulation
