【作者】 谢卫明； 何青； 张迨； 朱磊； 郭磊城； 王宪业；

【Author】 XIE Weiming;HE Qing;ZHANG Dai;ZHU Lei;GUO Leicheng;WANG Xianye;State key Laboratory of Estuarine and Coastal Research,East China Normal University;

【机构】 华东师范大学河口海岸学国家重点实验室；

【摘要】 河口潮滩位处陆海相互作用敏感带的最敏感区域,受径潮流的共同作用。在自然环境与人类活动的影响下,河口潮滩处于不断的动态调整中,其中大型人类工程往往会对河口潮滩短期地貌变化和沉积物特征产生巨大影响。2013年年底至2014年5月,长江口崇明东滩北部开展大规模互花米草治理工程,工程开展期间,抽泥排水,围堰造堤。本研究通过对工程前后潮滩地貌的观测、沉积物取样以及室内粒度分析,对比了工程前后潮滩地貌与沉积物特征的变化。结果表明,研究区域沉积物中值粒径介于7～60μm之间,沉积物类型以粉砂、砂质黏土、砂质泥和砂质粉砂为主。对比沉积物类型和各组分含量发现,本区由陆向海,砂含量逐渐增高;由南向北,黏土含量逐渐增高;工程修建过程中,整个盐沼植被带出现明显的冲刷,平均冲刷幅度达到4cm;而沉积物平均中值粒径则由工程前的29μm增大到工程完工后的38μm;潮滩不同区域地貌和沉积物变化对工程的响应存在明显的空间差异性。本文聚焦于研究人类围垦工程对河口潮滩的影响,既可增加对潮滩地貌变化控制因素的认识,也可为潮滩保护和管理提供很好的参考。更多还原

【Abstract】 The estuarine tidal flats,which are located at the interface between the oceans and the lands,are always under the influences of both river inputs and tidal currents.The morphological statuses of estuarine tidal flats are always being dynamic due to both human impacts and natural variations.The human modifications particularly show a strong influence on the short-term morphological changes and sediment characteristics in estuarine tidal flats.A huge embankment was construct in the Eastern Chongming tidal flats in the Yangtze Estuary from 2013 to 2014.Based on morphological surveys,sediment samples and laboratory analyses,this study aim to explore the response of morphology and sediment characteristics to human modification in an estuarine tidal flat.The results show that most of the sediments in the tidal flat are mud and the median particle sizes range from 7μm to 60μm.The sediment particle size shows an increase trend from land to sea and the ratio of clay increases from the south area to the north area.The entire tidal flat experiences significant erosion after the completion of the embankment,with a average decrease of 4 cm in elevation.The median particle size of the sediments increases from 29μm to 38μm after the construction.This study focus on exploring the influence that human modifications play on the estuarine tidal flats,which could gain a better understanding of the controls of tidal flat morphological changes and provide useful suggestions to the tidal flat managements.更多还原