近十年来长江口北支动力地貌演化过程  

Dynamic geomorphology evolution of the North Branch of the Yangtze River Estuary in recent ten years

作　　者：朱林 陈晓红 郭兴杰[3] 徐健 ZHU Lin;CHEN Xiaohong;GUO Xingjie;XU Jian(China Ocean Press Co.,Ltd.,Beijing 100161,China;Shanghai Waterway Department of Yangtze River,Shanghai 200010,China;Shanghai Institute of Geological Survey,Shanghai 200072,China;Shanghai Water Planning and Design Institute,Shanghai 200233,China)

机构地区：[1]海洋出版社有限公司,北京100161 [2]长江上海航道处,上海200010 [3]上海市地质调查研究院,上海200072 [4]上海市水务规划设计研究院,上海200233

出　　处：《上海国土资源》2022年第2期78-83,共6页Shanghai Land & Resources

基　　金：中国科技期刊卓越行动计划梯队期刊项目(卓越计划-C-047);上海市科委科研基金项目(20DZ1204704,21DZ1201700)。

摘　　要：北支是长江河口重要的分汊河道之一,其演化关系到通航条件、生态保护及河口工程的安全性,是水利学和海洋学界共同关注的话题。本文收集2007~2017年间河道实测断面数据,利用GIS技术对北支演化及其影响因素进行分析。结果表明:2007~2017年间长江口北支整体以侵蚀为主,共侵蚀泥沙量约13.97×10^(6) t,年均侵蚀厚度约0.46 cm,空间上呈中上段侵蚀,下段淤积,口门“北冲南淤”的变化特征;流域输沙减少和大量围垦采砂是北支近期河槽侵蚀和潮流沙脊消失的主要驱动因素,河道宽度和曲率的变化是引起北支冲淤空间差异的主要原因,地转偏向力对口门演化影响明显。鉴于北支的侵蚀演化已影响到滩涂湿地的发育,故建议未来北支周围省市应坚持“长江大保护”和“长三角一体化”等国家战略,协同保护北支的滩涂湿地。The North Branch is one of the important branch channels of the Yangtze River Estuary.Owing to the closely relationship with smooth navigation,ecological protection and estuary project safety,watercourse evolution of North Branch has received widespread attention in the field of hydraulics and oceanography.Based on the cross-sectional data between 2007 and 2017 and GIS technology,we analyzed the evolution characteristics and influencing factors in the North Branch.The results show that:(1)During 2007 to 2017,erosion was the domain phenomenon in the North Branch of Yangtze River Estuary,with a net erosion of~13.97×10^(6) t and an erosion rate of 0.46 cm/a.Net erosion occurred in the upper and middle reaches,while net siltation occurred in the lower reaches.(2)The reduction of sediment transport and a huge amount of tidal flat reclamations,played main driving factors for the erosion in the North Branch,as the same as the disappearance of tidal sand ridges.Changes of channel width and curvature are the main reasons for the spatial difference of erosion and deposition in the North Branch.The geostrophic force had an obviously influence on the evolution in the North Branch.(3)In light of the above findings,we suggested strengthen the coordinated development of regional economy,society and ecological environment in the future,to protect the tidal flats and wetlands in the North Branch.

关 键 词：长江口 北支 地形 侵蚀 动力地貌 演化过程 驱动因素 

分 类 号：P737.14[天文地球—海洋地质]