实验室内细颗粒泥沙沉降速度与悬沙浓度关系评估  

Evaluation of the Relationship Between Settling Velocity and Suspended Sediment Concentration for Fine Sediment in Laboratory

作　　者：唐杰平 陈德志 李高聪 TANG Jieping;CHEN Dezhi;LI Gaocong(School of electronic and information engineering,Guangdong Ocean University,Zhanjiang 524088,China;Fourth Institute of Oceanography,Ministry of Natural Resources,Beihai 536009,China)

机构地区：[1]广东海洋大学电子与信息工程学院,广东湛江524088 [2]自然资源部第四海洋研究所,广西北海536009

出　　处：《海洋技术学报》2023年第5期86-93,共8页Journal of Ocean Technology

基　　金：广东海洋大学科研启动经费资助项目(060302112104,060302112010);自然资源部热带海洋生态系统与生物资源重点实验室开放课题基金资助项目(2021QN02);广东省基础与应用基础研究基金资助项目(2022A1515240023)。

摘　　要：泥沙沉降速度是一个重要的沉积学参数,对于评估沉积物分布、扩散与物质输运等至关重要。对于细颗粒沉积物,悬沙浓度是影响沉降速度的一个关键因素,影响机制主要是絮凝作用和阻碍沉降效应,这个过程十分复杂,还无法使用通用的数学解析公式进行计算。本文介绍了一种简捷有效的室内评估细颗粒泥沙沉降速度的实验方法,并给出了沉降速度与悬沙浓度之间的关系。实验中研究的泥沙样品采集于废黄河口外,实验结果显示:当悬沙浓度小于1.5 g/L时,泥沙沉降速度随着悬沙浓度的增加而增加,当悬沙浓度大于2.5 g/L时,泥沙沉降速度随着悬沙浓度的增加而减小,当悬沙浓度达到14 g/L时,沉降速度降至约0.16 mm/s。整个实验过程中,当悬沙浓度达到1.5~2.5 g/L时,泥沙沉降速度最大,约为2 mm/s。本文介绍的实验,所需设备简单,实验过程简洁易行,实验结果稳定可靠,可以有效地用于不同研究区域泥沙沉降速度评估。Sediment settling velocity is a key parameter to evaluate the distribution,diffusion and transportation of sediment.Suspended sediment concentration affects sediment settling greatly controlling by the two mechanism of sediment flocculation and hindered settling.And the complex process made it impossible to calculate the settlement velocity using the general mathematical analytical formula.In this paper,a simple method in the laboratory was introduced to evaluate sediment settling velocity and its relationship with sediment concentration.As to the sediment collected outside the mouth of the abandoned Yellow River,the results of the indoor experiment showed that sediment settling velocity increased with the increase of sediment concentration when the concentration was less than 1.5 g/L,but the settling velocity decreased with the increase of sediment concentration when the concentration was more than 2.5 g/L.The maximum of sediment settling velocity was about 2 mm/s when the concentration was 1.5-2.5 g/L,however,the settling velocity was only 0.16 mm/s when the concentration reached 14 g/L.This experiment is simple and can evaluate settling velocity of fine-grained sediments effectively.

关 键 词：细颗粒泥沙 沉降速度 阻碍沉降 

分 类 号：P714.6[天文地球—海洋科学] P714.7