西北江三角洲河床变化对咸潮上溯影响的数值模拟研究  

Numerical Simulation Study on Influence of Riverbed Changes on Saltwater Intrusion in Northwest River Delta

作　　者：靳高阳[1] 朱三华[1] 曹一豪 JIN Gaoyang;ZHU Sanhua;CAO Yihao(China Water Resources Pearl River Planning,Surveying&Designing Co.,Ltd.,Guangzhou 510610,China;School of Civil Engineering,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]中水珠江规划勘测设计有限公司,广东广州510610 [2]中山大学土木工程学院,广东广州510275

出　　处：《人民珠江》2024年第3期89-98,共10页Pearl River

基　　金：国家自然科学基金(U1911204、51861125203);国家重点研发计划项目(2021YFC3001000)。

摘　　要：为研究西北江三角洲河床变化及其与咸潮上溯关系,收集整理以往研究成果资料与水文气象、河道地形数据的基础上,建立一维非恒定流含氯度数学模型,水动力和含氯度验证结果均满足相关规范要求,可以用于计算分析河床变化对咸潮上溯的影响。研究结果表明:①1999—2016年,西北江三角洲网河区河床处于不均匀下切状态,河道容积持续增大,导致河口涨落潮阻力减小,高盐水团沿河口上溯更为简单,咸潮上溯情势日益严峻;②各口门站的涨潮量增加,咸界上移取淡机率降低,思贤滘不同来流条件下,磨刀门水道咸界平均上移3735 m,平岗泵站的取淡机率平均减少5.33%,沙湾水道咸界平均上移2369 m,沙湾第一水厂取淡机率平均减少5.14%,严重影响河口地区的生态系统以及正常取水需求。研究结果可以为西北江三角洲及河口地区的供水安全保障措施研究及工程设计提供基础支撑。To study the changes in the riverbed of the Northwest River Delta and their relationship with saltwater intrusion,this paper builds a one-dimensional unsteady flow chlorine concentration mathematical model based on the collection and organization of previous research results,hydrological,meteorological,and river terrain data.The hydrodynamic and chlorine concentration verification results meet the relevant regulatory requirements and can be applied to calculate and analyze the impact of riverbed changes on saltwater intrusion.The research results are as follows.①From 1999 to 2016,the riverbed of the Northwest River Delta network was in an uneven downward cutting state,and the volume of the river continued to increase,resulting in a decrease in the resistance of the estuary to rising and falling tides.The upward tracing of high saltwater masses along the estuary was simpler,and the upward tracing of salt tides became increasingly severe.②The rising tide at each Koumen station increases,and the probability of removing freshwater from the saltwater boundary decreases.Under different inflow conditions in Sixianjiao,the average upward movement of the saltwater boundary at Modaomen Waterway is 3735 m,and the average downward movement of the freshwater from Pinggang Pumping Station is 5.33%.The average upward movement of the saltwater boundary at Shawan Waterway is 2369 m,and the average downward movement of the freshwater from Shawan No.1 Water Plant is 5.14%.These seriously affect the ecosystem and normal water intake demand in the estuarine area.The research results can provide basic support for the research and engineering design of water supply safety measures in the Northwest River Delta and estuarine areas.

关 键 词：河床演变 含氯度 数学模拟 咸潮上溯 咸界变化 

分 类 号：TV8[水利工程—水利水电工程]