华东师范大学学报(自然科学版) ›› 2017, Vol. ›› Issue (4): 149-159.doi: 10.3969/j.issn.1000-5641.2017.04.013

• 河口海岸学 • 上一篇    下一篇

悬浮絮凝体特征及其影响因子的综合作用——以长江口内河槽和口门最大浑浊带为例

杨天1, 杨世伦1, 杨海飞1, 朱琴1, 张文祥1, 张朝阳2, 王如生3   

  1. 1. 华东师范大学 河口海岸学国家重点实验室, 上海 200062;
    2. 长江口水文水资源勘测局, 上海 200136;
    3. 国家海洋局 第二海洋研究所, 杭州 310012
  • 收稿日期:2016-10-26 出版日期:2017-07-25 发布日期:2017-07-20
  • 通讯作者: 杨世伦,男,教授,研究方向为海岸沉积动力学和地貌学.E-mail:slyang@sklec.ecnu.edu.cn. E-mail:slyang@sklec.ecnu.edu.cn
  • 作者简介:杨天,男,硕士研究生,研究方向为河口动力沉积与地貌.E-mail:yangtian1018@qq.com.
  • 基金资助:
    科技部重点专项（2016YFA0600901）；国家自然科学基金委-山东省联合基金项目（U1606401）

Characteristics of suspended flocs and the combined action of contributing factors in Yangtze Estuary: A case study on the significant differences between the inner estuary and the mouth area

YANG Tian1, YANG Shi-lun1, YANG Hai-fei1, ZHU Qin1, ZHANG Wen-xiang1, ZHANG Chao-yang2, WANG Ru-sheng3   

  1. 1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China;
    2. Survey Bureau of Hydrology and Water Resources of Changjiang Estuary, Shanghai 200136, China;
    3. Second Institute of Oceanography State Oceanic Administration, Hangzhou 310012, China
  • Received:2016-10-26 Online:2017-07-25 Published:2017-07-20

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摘要： 絮凝对河口细颗粒悬沙运动起着极其重要的作用.为深入探讨长江口悬浮絮凝体的特征及其主要影响因子的综合作用，于2014年10月19-23日（长江口径流量、潮差、风浪均接近多年平均值）利用多种仪器在人类活动干扰较小的南支-北港-口外海滨水域进行了综合现场观测和取样，获得了四个潮流特征时刻（涨急、涨憩、落急、落憩）的悬浮絮凝体粒径、分散粒径（即分散悬沙的原始粒径）、悬沙浓度、体积浓度、流速流向、盐度等数据.利用灰色关联度分析方法分析五大影响因子（悬沙浓度、体积浓度、流速、盐度和分散粒径）对絮凝体粒径和有效密度影响程度.结果表明，在相同体积水体中，口门最大浑浊带测点的絮凝体相对口内河槽测点数量多、粒径小，絮凝体内粘土颗粒少、空隙大、自由水多.在口内河槽，絮凝体粒径主要受悬沙浓度、分散粒径和体积浓度控制，有效密度主要受到分散粒径、悬沙浓度和流速控制；在口门最大浑浊带，絮凝体粒径的主控因子是流速，有效密度主要受到盐度、悬沙浓度控制.

关键词: 悬浮絮凝体, 影响因子, 灰色关联度分析法, 长江口

Abstract: Flocculation plays a vital role in the transport of estuarine fine suspended sediments. To study the natural situation and the main influencing factors of fine suspended sediment flocculation, in-situ observations were carried out along the South Branch to the North Channel of the Yangtze Estuary from 19th to 23th October 2014 (During that time, river discharge, tidal range and wind waves have same value to annual mean value). Floc size, dispersed particle size, volume concentration (VC), suspended sediment concentration (SSC), salinity, temperature and flow velocities were measured at four characteristic moments at four sites. We study the relation between median floc size, as well as effective density, and the five influencing factors with the Grey relational analysis.The results shows that,in the same water volume, flocs in the Turbidity Maximum Zone has more floc numbers and smaller floc size; that floc inside has less clay particles, larger gap and more free water compare to the inner estuary. In the inner estuary,critical factors influencing floc sizes are SSC, dispersed particle size, VC, and critical factors influencing effective density were dispersed particle size, SSC, velocity. In the Turbidity Maximum Zone of the mouth area, the critical factor influencing floc sizes is velocity and the critical factors influencing effective density are salinity and SSC.

Key words: suspended flocs, influencing factors, grey relational analysis, Yangtze Estuary

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