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本文以鸭绿江口西汊道连续性较好、时间分辨率较高、以海湾性质为主的2处现代沉积物为样本,对其沉积速率、粒度特征、碎屑矿物、重金属进行了测定和分析。柱状样记录了1920年以来西汊道上游的沉积过程,平均沉积速率约为0.98cm/a,粒度参数、指示性碎屑矿物、重金属的垂向分布显示出这里的沉积是以海相河口湾沉积为主,但交替存在河流沉积。通过与前期研究成果的比较,揭示了近百年来人类活动对鸭绿江口河床演变的影响。其中,兴修水利对河床演变的影响集中在早期,并带来了河床地貌的重大改变,西汊道失去了河流主汊道的地位;围垦带来的河床演变出现在中期,对河床地貌的影响也很深刻,表现为陆域面积不断扩大,水域面积不断缩小;航道治理等人类活动对河床演变的影响出现在中后期,河床地貌没有明显的改变;最近的人类活动影响有待观察。
In this paper, the West Yalu River in the Yalu River estuary is relatively good and the time resolution is relatively high. Two modern sediments, mainly of the Gulf, are taken as samples to measure and analyze the deposition rate, grain size, detrital minerals and heavy metals . Columnar samples recorded the deposition of the upper Xiwudao channel since 1920, with an average deposition rate of about 0.98 cm / a. The vertical distribution of grain size parameters, indicative detrital minerals and heavy metals showed that the sediment was dominated by marine estuaries Sediment-based, but alternating river deposits. Through the comparison with the previous research results, it reveals the influence of human activities on the riverbed evolution of the Yalu River in the past hundred years. Among them, the influence of Xingshui water conservancy on the riverbed evolution concentrated in the early stage, which brought about major changes in the riverbed landscape and the loss of Xihu Road to the river main road; the riverbed evolution brought by reclamation appeared in the middle period and affected the riverbed landform But also the impact of human activities such as waterway management on the riverbed evolution appeared in the late period. There was no obvious change in riverbed landform; the effect of human activities to be observed recently was yet to be observed.