椒江河口春季悬沙输运特征及通量机制研究  

Suspended transportation and flux mechanism of sediment in the Jiaojiang Estuary in spring

作　　者：刘伟 范代读[1] 涂俊彪[1] 芦军[1] 

机构地区：[1]同济大学海洋地质国家重点实验室,上海200092

出　　处：《海洋地质与第四纪地质》2018年第1期41-51,共11页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目"人类活动影响下长江口北支动力地貌演化与沉积地层格架研究"(41776052);科学科技基础性工作专项"典型中小入海河流河口动力沉积地貌与环境本底数据调查"(2013FY112200);中国东盟海上合作基金"长江三角洲与红河三角洲全新世沉积演化对比研究"

摘　　要：通过分析2016年3月椒江河口两个定点站位的潮周期水文泥沙观测数据,研究了椒江河口春季悬沙输运特征及通量机制。结果表明,河口内侧站位潮流速大于外侧站位值,两站位垂线平均悬沙浓度分别为0.3~5.8kg/m^3和0.3~1.0kg/m^3。悬沙通量机制分解表明,内侧站以向海的潮泵输沙效应最显著,对单宽输沙量绝对值贡献率为43.9%,其次是向陆的平流和垂向净环流输沙,综合作用下悬沙向陆净输移0.39kg/(m·s);外侧站位以向海的平流输沙为主导作用,贡献率为72.6%,悬沙向海净输移0.10kg/(m·s)。小波分析和频谱分析表明,含沙量、输沙率及流速三者之间存在不同的响应关系,内侧站输沙率主要受流速的影响,而外侧站位则主要受控于悬沙浓度变化。A detailed study on hydrodynamic characteristics and transportation mechanisms of suspended sediment at two specific sites of the Jiaojiang Estuary were conducted in March,2017.The data resulted from the observation at anchor stations show that the Jiaojiang Estuary is characterized by a bidirectional field of currents,and the tidal currents at the stations within the river mouth are obviously stronger than that at the sites located outside the river mouth.The depth-mean SSCs at the two stations are 0.3~5.8 kg/m^3,and 0.3~1.0 kg/m^3,respectively.The results of mechanism decomposition of sediment transport indicate that at the upstream site,the dominant mechanism of transporting suspended sediment is the seaward tidal pumping,which contributes 49.3% of the total absolute sediment flux,followed by the landward advection and the vertical net circulation.As the result,the net suspended sediment transport is 0.39 kg/（m·s）landward.However,the sediments fluxes at the downstream station are dominated by the seaward advection,with 72.6% of contribution,and the net suspended sediment transport is 0.10 kg/（m·s）seaward.The three-layers wavelet analysis and spectral analysis suggest that there are somewhat coupling response relations between the SSC and the sediment transport rate and flow velocity.The sediment transport rate is dominated by the flow velocity at the outer site of the estuary,and SSCs at the site inside.

关 键 词：椒江河口 机制分解 潮泵作用 平流输沙 小波分析 

分 类 号：X141[环境科学与工程—环境科学]