中文摘要：

基于鸭绿江口主汊道10个沉积柱的粒度分析,讨论了鸭绿江口水动力条件、物源输入、沉积事件等沉积环境的演化过程。沉积记录显示,空间上自陆向海潮流对沉积的影响逐渐加强,时间上从上层到下层的径流影响逐渐减弱。沉积物的敏感粒度分析表明,细组分可能来源于鸭绿江径流;粗组分大部分来源于径流悬移质中的较粗部分和跃移质,少部分来源于浅海潮流脊的物质。在可识别的9个沉积事件中,4个与洪水直接相关,其他也表现出对环境事件或流域变化的响应。1960年的沉积事件非常重要,导致了河口地貌＂二级分汊,三口入海＂的重大地貌格局的形成。鸭绿江河口三角洲沉积与西岸潮滩的沉积具有＂耦合效应＂,1970年、1988—1992年和1995年的沉积事件在鸭绿江口西汊道及西岸潮滩剖面中同样存在,可以用来进行地层的划分和对比。

英文摘要：

Ten cores are collected along the Main Branch of the Yalu River estuary. Dating and grain size analysis are made for the cores layer by layer. The data of grain size is used in this paper for revealing the evolution of depositional environment. Hydrodynamic conditions, source input and depositional events are discussed as major topics. The results indicate that the influence of tidal current increased from land to sea spatially, and the runoff influence weakened gradually with time. The fine fractions of sediments came mainly from the runoff of the Yalu River, and most of the coarse fractions were from the coarser suspended load and saltation load, and few of them came from tidal ridges offshore. Nine depositional events are identified, among which four were directly related to flooding, and the others related to changes in environ- ment and/or drainage. The 1960 event was certainly a significant one which led to the changes in landform pattern, including the formation of secondary branching, and three outlets towards the sea. The deltaic deposits at the Yalu River are well correlated with the tidal flat deposits on the west bank. Depositional events in 1970, 1988 to 1992 and 1995 are all recognizable in the profiles of the West Branch as well as the tidal flat in the west bank, and could be used as marks for sequence classification and correlation.