交汇区水流结构对底泥磷分布特征影响机制  

Influence mechanism of flow structure on distribution characteristics of phosphorus on bed sediments at river confluences

作　　者：夏阳 周苏芬 邹俊 胡健 XIA Yang;ZHOU Sufen;ZOU Jun;HU Jian(Jiangxi Academy of Water Science and Engineering,Nanchang 330029,China;Jiangxi Provincial Technology Innovation Center for Ecological Water Engineering in Poyang Lake Basin,Nanchang 330029,China;College of Harbour,Coastal and Offshore Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]江西省水利科学院,南昌330029 [2]江西省鄱阳湖流域生态水利技术创新中心,南昌330029 [3]河海大学港口海岸与近海工程学院,南京210098

出　　处：《南水北调与水利科技（中英文）》2024年第3期595-604,共10页South-to-North Water Transfers and Water Science & Technology

基　　金：国家重点研发计划项目(2022YFC3201804;2022YFC3202603);江西省水利厅科技项目(重大)(202124ZDKT18)。

摘　　要：交汇区的水流结构极为复杂,揭示交汇区底泥磷分布特征难度较大。设计交汇区底泥磷分布实验系统及其检测方法,测量交汇区的三维流场和底泥中总磷含量,分析交汇区水流分区与底泥中总磷空间分布的关系,并基于交汇水槽实验中204组水动力参数与底泥中总磷含量数据,建立人工神经网络模型,定量分析流场中水动力参数对底泥中总磷含量的影响,辨识其中的关键水动力参数。结果表明:分离区内水流水平流速较小,底泥磷含量较高;位于分离区外侧的加速区水平流速较大,底泥磷含量较低,但加速区的局部区域(剪切层区)存在显著的底泥磷含量偏高现象;通过人工神经网络模型的参数敏感性分析,定量解释局部底泥磷含量高值现象与该区域较大的向下水流有关。River systems,particularly plain river systems,are rich in fine-grained sediments,which exhibit a significant adsorption capacity for phosphorus.The fine-grained sediments play a significant role in river water pollution,serving as both sources and sinks for pollutants.The confluence zone is a crucial node for phosphorus transport and deposition in river systems.Due to the complex flow structure in this area,it is difficult to reveal the distribution characteristics of phosphorus on bed sediments at river confluences.An experimental system and detection method were designed to investigate the distribution of phosphorus on bed sediments within the confluence zone.The three-dimensional flow field of the confluence and the total phosphorus content of the bed sediments were measured.Subsequently,the relationship between the flow zone and the spatial distribution of total phosphorus on the bed sediments was analyzed.Based on 204 sets of hydrodynamic parameters and total phosphorus content data obtained from the confluence experiment,an artificial neural network model was established to quantitatively analyze the influence of hydrodynamic parameters within the confluence zone on the total phosphorus content of bed sediments,thereby identifying the key hydrodynamic parameters.The results show that:(1)Under the condition of large confluence ratio(Qr=0.6),the total phosphorus content of bed sediments in the separation zone and the shear layer zone was high,indicating zones with high occurrences of phosphorus.The total phosphorus content of bed sediments in the acceleration zone was 21.4%lower than that in the separation zone,indicating a zone with low phosphorus occurrence.Under the condition of small confluence ratio(Qr=0.4),except for sediments in the shear layer zone,which exhibited a high phosphorus content,the other areas exhibited a comparatively low phosphorus content.(2)The low horizontal flow velocity in the separation zone facilitated the migration of phosphorus from the water body to the bed sediments,resulting

关 键 词：河流交汇区 底泥磷 分布特征 水流结构 人工神经网络模型 

分 类 号：TV68[水利工程—水利水电工程] TV9