地理学报 ›› 2018, Vol. 73 ›› Issue (11): 2105-2116.doi: 10.11821/dlxb201811005

• 气候变化与地表过程 • 上一篇    下一篇

近百年来长江口启东嘴潮滩沉积物质来源及定量估算

张云峰1(),张振克2,任航2,高磊3,丁海燕1   

  1. 1. 盐城师范学院江苏沿海开发研究院,江苏 盐城 224007
    2. 南京大学地理与海洋科学学院,南京 210023
    3. 中国科学院南京地理与湖泊研究所,南京 210008
  • 收稿日期:2017-12-08 出版日期:2018-11-25 发布日期:2018-11-22
  • 基金资助:
    国家自然科学基金(41501003, 41701101, 41371024, 41771199);江苏省高校哲学社会科学研究项目(2013SJD790028);江苏省高校自然科学研究项目(14KJD170005, 14KJA170006);江苏省自然科学基金项目(BK20160446)

The sediment sources and quantitative evaluation of tidal flat at Qidong foreland, the Yangtze Estuary in recent 100 years

ZHANG Yunfeng1(),ZHANG Zhenke2,REN Hang2,GAO Lei3,DING Haiyan1   

  1. 1. Research Institute of Jiangsu Coastal Development, Yancheng Teachers University, Yancheng 224007, Jiangsu, China
    2. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
    3. Nanjing Institute of Geography & Limnology, CAS, Nanjing 210008, China;
  • Received:2017-12-08 Online:2018-11-25 Published:2018-11-22
  • Supported by:
    National Natural Science Foundation of China, No.41501003, No.41701101, No.41371024, No.41771199; Philosophy and Social Sciences Foundation of the Jiangsu Higher Education Institutions of China, No.2013SJD790028; Natural Science Foundation of the Jiangsu Higher Education Institutions of China, No.14KJD170005, No.14KJA170006; Natural Science Foundation of Jiangsu Province, China, No.BK20160446

摘要:

河流入海输沙是海岸稳定的重要物质基础。启东嘴潮滩位于长江北支口门,与江苏海岸线交汇,陆海相互作用强烈。利用电感耦合等离子体质谱仪测定了岩芯沉积物QDZ-1的地球化学元素。根据地球化学元素的分布特征和富集系数,分析了物源指示意义,表明启东嘴潮滩沉积物受到长江物质和南黄海物质的共同影响。基于地球化学元素的沉积物端元定量判识方法,对不同物质来源的贡献率进行了定量估算。在1930年前启东嘴潮滩沉积物主要来自长江的入海输沙,贡献率为68.1%,随着长江北支河槽的衰退,贡献率逐渐减少,在1930-1972年间为38.5%,到1972年后减少到17.5%。苏北沿岸流携带向南输运的南黄海物质,贡献率逐渐增加,在1930年前为27.1%,在1930-1972年间为55.6%,到1972年后增加到75.9%,成为启东嘴潮滩主要物质来源。沉积物来源的阶段性变化,在时间上与北支水动力的阶段性变化基本吻合。

关键词: 长江口, 启东嘴潮滩, 物质来源, 环境变化, 定量估算

Abstract:

The transport of sediment by rivers to the oceans plays an important role in coastal stabilization. The Qidong foreland is located on the junction between Yangtze Estuary and Jiangsu coast, where strong land-ocean interactions are highly sensitive to environmental changes. In order to examine sediment sources and change, QDZ-1 core sediments were collected at Qidong foreland tidal flat. And the content of micro-elements was analyzed by ICP-MS, further, the source-indicating significance of micro-elements was discussed based on distribution and enrichment coefficient. The result showed that sediment sources derive from the Yangtze River and the south Yellow Sea. In addition, sediment sources were quantitatively evaluated by estimation of sedimentary end-members. The result showed that sediment sources could be divided into three stages. The sediment flew mainly from the sediment transport of the Yangtze River into the sea, with the contribution rate being 68.1%. Then, the contribution rate gradually decreased with the decline of the North Branch, down to 38.5% during the period of 1930-1972, and to 17.5% after 1972. Meanwhile, the suspended sediments from southern Yellow Sea moved mainly to the south by strong tide and Subei coastal current, and the contribution rate was 27.1% before 1930. Subsequently, the contribution rate gradually increased, up to 55.6% during the period of 1930-1972, and to 75.9% after 1972. The sediment sources of Qidong foreland tide flat mainly transformed from the Yangtze sediment to the south Yellow Sea sediment. The changes in stages of sediment source were consistent with the decline of the North Branch.

Key words: Yangtze estuary, Qidong foreland tide flat, sediment sources, environmental significance, quantitative evaluation