摘要
结合1998-2018年期间长江口南支河段的实测沙波微地貌资料、海图资料和实测水深数据以及河槽沉积物资料,分析和探讨南支河段河槽演变过程及其对人类活动的响应。结果表明:三峡及上游梯级水库作用下已导致进入河口的泥沙量呈现持续锐减,引起南支河段在1998-2018年期间的河槽持续受到冲刷,净冲刷和平均每年冲刷的泥沙体积分别达5.16亿m^(3)和0.26亿m^(3),且冲刷程度在2002-2018年期间明显大于1998-2002年期间。近期南支河段河槽床面以细砂为主,床面发育大范围的沙波微地貌,沙波尺度以中型为主,平均波高和波长分别为0.56 m和10.57 m,占比达60.91%,沙波形态主要受径流作用的控制,冲刷环境可能引起沙波发育的空间范围进一步向下游推进。
Micromorphology investigation on the South Branch of the Yangtze River Estuary by the multi-beam bathymetric data was studied in the 2015 August.The physical properties of the micromorphology were assessed by grain size analysis of bottom sediment samples.Digital bathymetric data during 1998-2018 were also used to access long-term morphological changes of the riverbed and were affected by human activities.Results show that the continual channel bed scour occurred in the South Branch from 1998 to 2018.The net volume loss and average annual net volume loss reached 5.16×10~8 m^(3) and 0.26×10~8 m^(3) respectively,due to significant decrease of sediment supply caused by the Three Gorge Dam.Compared to the scour intensity of the South Branch during 1998-2002,the channel bed experienced extremely strong scour from 2002 to 2018.The bottom sediment distribution in the South Branch is mainly composed of fine sand.There was a large area of dunes developed in the South Branch.Medium dunes were predominant,amounting to 60.91%.The average height and length were 0.56 m and 10.57 m,respectively.Severe channel scour and coarse sand supply may contribute to the downstream movement of the dune zone.
作者
吴帅虎
程和琴
WU Shuai-hu;CHENG He-qin(School of Resources Environment and Tourism,Anyang Normal University,Anyang 455000,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China;State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200062,China)
出处
《泥沙研究》
CAS
CSCD
北大核心
2022年第6期74-80,共7页
Journal of Sediment Research
基金
国家自然科学基金项目(41476075)
河南省自然科学基金青年项目(212300410101)。
关键词
长江河口
南支
冲淤变化
微地貌
Yangtze River Estuary
South Branch
erosion and deposition
micromorphology
作者简介
吴帅虎(1986-),男,陕西西安人,讲师,博士,主要从事河口海岸工程地貌方面研究。E-mail:wushuaihuxiaolaoda@163.com。
