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沉积速率是认识潮滩沉积地貌环境变化的重要环境指标.长江口启东嘴潮滩位于长江北支沿江岸线和江苏沿海岸线的交汇处,是典型的粉砂淤泥质潮滩.对采集的岩芯沉积物QDZ-1进行了137Cs同位素测年和粒度分析.结果表明岩芯沉积物以粉砂为主,从底部到表层表现为由粗变细的趋势,符合粉砂淤泥质潮滩的沉积特征.多年平均沉积速率在1963—1986年为2.61cm/a,在1963—2011年为1.82cm/a,在1986—2011年为1.10cm/a.基于此,对环境变化的意义进行了进一步解释.在深度172.5cm处砂含量突然增加,根据沉积速率估算,可能是长江流域1931年洪水等极端环境变化的影响.自从大规模引种互花米草后,保堤促淤效果显著,潮滩地貌由侵蚀转变为淤积,随着潮滩的逐渐淤高,由低潮滩转变为高潮滩,沉积速率呈现逐渐下降的趋势.“,”The sedimentation rate is one of the important environmental parameters to understand the evolution of coastal geomorphology.The tidal flat around Qidong foreland is located in the junction between Yangtze Estuary and Jiangsu coast, where the land-ocean interactions air strong and highly sensitive to environmental changes.The QDZ-1 core sediments collected at Qidong foreland was analyzed for 137Cs dating and grain size.The results showed that, silt is the main sedimentary type with a trend of gradually fining from the bottom to the top.The sedimentation rate could be divided into distinct stages:1963 to 1986 was 2.61 cm/a, 1963 to 2011 was 1.82 cm/a, 1986 to 2011 was 1.10 cm/a.Furthermore, the environment significances were explained by using the sedimentary records.According to the estimation of sedimentation rate, the impact of extreme environmental change was reflected by the sudden increase in sand proportion at the depth of 172.5 cm.The Spartina Alterniflora has been introduced since 1970 s, which played an important role in tidal flat development.The tied flat has a high sedimentary rate during this time.With the tidal flat continuous accretion, low tide beach turns to high tide beach, sedimentary rate is gradually reduced, and tidal flat sedimentation appears.