长江输沙量减少对河口典型浅滩断面泥沙输运的影响研究  

Influence of sediment transport reduction in the Yangtze River on sediment transport in typical shoal sections of the estuary

作　　者：陈肖慧 张国安[1] 张卫国[1] 李茂田[1] CHEN Xiao-hui;ZHANG Guo-an;ZHANG Wei-guo;LI Mao-tian(State Key Laboratory of Estuarine and Coastal Sciences,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200241

出　　处：《泥沙研究》2021年第6期44-50,共7页Journal of Sediment Research

基　　金：国家重点研发计划项目(2017YFE0107400);上海市科委项目(18DZ1206401)。

摘　　要：河流入海泥沙是河口三角洲长期演变的物质基础。河口浅滩是河口三角洲典型的地貌现象,对河口三角洲演变具有重要的指标意义。近30年来长江入海泥沙锐减,三角洲沉积环境发生显著变化。基于长江河口典型浅滩断面的综合调查成果,研究长江泥沙减少背景下河口典型浅滩断面泥沙输移特性和机制。研究结果表明:河流入海泥沙主要向东扩散和向南沿岸输运,东西方向2 m和5 m等深线出现表层和底层净输沙分异现象;余流空间分布控制泥沙净输运趋势,水体高含沙量对泥沙净输移作用显著。北侧浅滩断面水下斜坡已处于略有冲刷状态,南侧受到北侧沿岸输沙补给减少的影响,淤积速率放缓。River sediment into the sea is the material basis for the long-term evolution of the estuary delta. The estuary shoal is a typical geomorphic phenomenon in the estuary delta,which is an important indication for the process of the estuary delta. In the past 30 years,the sediment from the Yangtze River has reduced sharply,which has caused significant changes in the delta sedimentary environment. Based on the comprehensive survey results of the typical shoal section of the Yangtze River estuary,the paper studies the characteristics and mechanism of sediment transport in the typical shoal section of the Yangtze River estuary under the background of the reduction of sediment into the sea. The results show that the sediment from the river flowing into the sea is mainly transported eastward and southward. In the east-west direction,the 2 m and 5 m isobaths have different directions of net sediment transport on the surface and bottom. The spatial distribution characteristics of residual current control the trend of net sediment transport in the estuary delta. The distribution characteristics of high sediment content have a significant effect on the net transport intensity of sediment. Under the background of the drastic reduction of sediment sources in the river basin,the shoal section on the north side of the delta is already in a slightly eroded state. Due to the replenishment of sediment on the north side,the deposition of the shoal section on the south side of the delta slows down.

关 键 词：入海泥沙锐减 典型浅滩断面 泥沙输移 沉积环境 

分 类 号：TV148.1[水利工程—水力学及河流动力学]