地理学报 ›› 2019, Vol. 74 ›› Issue (3): 572-585.doi: 10.11821/dlxb201903013

• 气候变化与地表过程 • 上一篇    下一篇

20世纪50年代中期以来崇明岛东部盐沼发育对长江入海泥沙的响应

姚振兴(), 陈庆强(), 杨钦川   

  1. 华东师范大学河口海岸学国家重点实验室,上海 200062
  • 收稿日期:2018-03-12 修回日期:2018-12-15 出版日期:2019-03-25 发布日期:2019-03-19
  • 作者简介:姚振兴(1992-), 男, 浙江嘉兴人, 硕士生, 主要从事海洋沉积研究。E-mail: <email>yaozhenxing050608@126.com</email>
  • 基金资助:
    国家自然科学基金项目(41471161);National Natural Science Foundation of China, No.41471161

Response of evolution of the salt marsh in eastern Chongming Island to the sediment discharge from Yangtze River after mid-1950s

Zhenxing YAO(), Qingqiang CHEN(), Qinchuan YANG   

  1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
  • Received:2018-03-12 Revised:2018-12-15 Online:2019-03-25 Published:2019-03-19

摘要:

以20世纪50年代中期以来崇明岛东部盐沼6个钻孔潮坪层段为研究对象,根据柱样粒度特征、碳/氮元素含量、有机碳稳定同位素组成(δ13C)和C/N比,结合长江入海泥沙通量的变化,研究20世纪50年代中期以来崇明岛东部盐沼发育与长江入海泥沙的响应关系。结果表明:长江入海泥沙通量及组成是20世纪50年代中期以来崇明岛东部盐沼物质粗细变化的主控因素;崇明岛东部盐沼沉积物δ13C与C/N比的相关程度、有机质含量与各粒径区间颗粒含量的相关性在不同时期均存在差异;20世纪60年代,长江入海泥沙量达到顶峰,流域不同侵蚀区域的泥沙相互混合,有机质含量与各粒径区间颗粒含量的相关性及δ13C与C/N比的相关程度均很差;20世纪90年代以来,崇明岛东部地区进行了高强度的围垦活动,δ13C与C/N比的相关程度下降。这表明20世纪50-80年代崇明岛东部盐沼发育受长江入海泥沙控制,20世纪90年代以来崇明岛东部盐沼发育除受长江入海泥沙控制外,还受围垦等人类活动的显著影响。

关键词: 物源分析, 长江年入海沙量, 围垦, 盐沼, 崇明岛

Abstract:

Response of evolution of the salt marsh to the sediment discharge from Yangtze River was studied, based on the analyses of grain sizes, contents of particulate organic carbon (POC) and total nitrogen (TN), stable carbon isotope (δ13C) and C/N ratios for six cores in the eastern part of Chongming Island salt marsh after mid-1950s, as well as the change characteristics of the sediment discharge from Yangtze River. Results indicated that the change of the grain size for the eastern part of Chongming Island salt marsh after mid-1950s was controlled by the sediment discharge from the Yangtze River. Correlations between contents of organic matter (POC and TN) and contents of grains in different size fractions, and between δ13C and C/N ratios are different for six cores. In the 1960s, the sediment discharge from the Yangtze River was the most, and the sediments in different reaches of the river mixed with each other. This led to both poor correlations between the contents of organic matter (POC and TN) and contents of grains in different size fractions, and between δ13C and C/N ratios, respectively. There has been a decline of the correlations between δ13C and C/N ratios for the heavy reclamation since the 1990s. This indicated that evolution of the salt marsh in the eastern part of Chongming Island was controlled by the sediment discharge from the Yangtze River from the 1950s to the 1980s. Since the 1990s, evolution of the salt marsh in the eastern part of Chongming Island has been not only controlled by the sediment discharge from the river, but also influenced by human activities such as reclamation.

Key words: provenance analysis, sediment discharge from Yangtze River, reclamation, salt marsh, Chongming Island