长江口启东嘴潮滩沉积特征及对人类活动的响应  

The sedimentary characteristics and its response to human activity at tidal flat around Qidong cape,the Yangtze estuary

作　　者：张云峰 张振克[2] 张华兵 陈影影 蒋玉波 ZHANG Yunfeng;ZHANG Zhenke;ZHANG Huabing;CHENYingying;JIANG Yubo(Research Institute of Jiangsu Coastal Development,Yancheng Teachers University,Yancheng 224007,China;School of Geography and Ocean Science,Nanjing University,Nanjing 210023,China;School of Geography,Geomatics and Planning,Jiangsu Normal University,Xuzhou 221116,China)

机构地区：[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,江苏南京210023 [3]江苏师范大学地理测绘与城乡规划学院,江苏徐州221116

出　　处：《海洋湖沼通报》2021年第3期62-69,共8页Transactions of Oceanology and Limnology

基　　金：国家自然科学基金(41501003,41701101,41807403);江苏沿海开发研究院开放课题(RIJCD11008);江苏省高校自然科学研究项目(18KJB170021)资助。

摘　　要：随着社会经济的快速发展,潮滩受到的人类活动的影响也越来越大。长江口启东嘴潮滩位于江苏海岸与长江岸线交汇处,现代人类活动不断增强,潮滩沉积环境发生显著变化。对采集的四个岩芯沉积物进行了粒度分析。结果表明:(1)岩芯QDZ-1、QDZ-2、QDZ-3沉积物主要为粉砂,体现了潮滩沉积的一般规律,从底部到表层沉积物逐渐变细。在剖面下部多次出现的砂含量突然增加并伴有贝壳碎屑沉积,是因为受到极端环境变化的影响。(2)盐沼植物能够有效降低水动力能量和吸附细颗粒泥沙,互花米草引种后消浪促淤作用显著。随着潮滩高程的逐渐淤高,由低潮滩转变为高潮滩,沉积速率逐渐下降,经历了由快到慢的沉积过程。(3)人类活动会使潮滩表现出不同于自然状态下的沉积特征。岩芯QDZ-2在深度32.5 cm以上沉积物出现粗化趋势,是因为受到轮作翻种的农业生产活动影响。柱样QDZ-3在深度37.5 cm以上和岩芯YTJ-4沉积物表现出粗化的趋势,原因是围垦建堤增强了沉积动力环境,粗颗粒物质能够适应高能环境而得以沉积。The tidal flat sedimentary environment is influenced by strong human reclamation activities with economic development.Tidal flat around Qidong cape is located at the intersection between the coast of Jiangsu and the river line of the Yangtze River,where has intense modern human activities.The result show that great changes have taken place in sedimentary environment.In order to analyze the sedimentary characteristics and its response to human activity,four cores are collected during field investigation and tested based on grain size.The results showed that:(1)the cores QDZ-1,QDZ-2 and QDZ-3 are mainly composed of silt,which could reflect general law of tidal flat sedimentation.The sediments tend to thinned from bottom to surface.Under the influence of extreme environmental changes,there are multiple times sand content increased suddenly in the lower part of cores profile with shell debris deposition.(2)Salt marsh plants play an important role in reducing effectively hydrodynamic energy and adsorbing fine-grained sediments.With gradual siltation of tidal flat elevation and changing from low-tidal flat to high-tidal flat,the sedimentation rates decreased gradually,and the cores undergone a deposition process from fast to slow.(3)There are different sedimentary characteristics from natural environment under the influence of human activity.Core QDZ-2 showed a clear tendency of upward coarsening at upper 32.5 cm depth.The reason is that fine-grained fraction is more than coarse-grained fraction leached loss by rainwater under influence of the rotation of agricultural activities.Core QDZ-3 showed a clear tendency of upward coarsening at upper 37.5 cm depth.And core QDZ-4 showed the same tendency with QDZ-3 at whole profile.The reason is that the sedimentary dynamic is enhanced by reclamation dikes constructed.And coarse-grained fraction is easier than fine-grained fraction to adapt to high-energy environment and then to deposit.

关 键 词：长江口 启东嘴潮滩 粒度特征 人类活动 环境变化 

分 类 号：K903[历史地理—人文地理学] P512.5[天文地球—地质学]