根据鸭绿江河口西水道水流、悬浮泥沙和底质粒度特征的分析，研究丹东港出海航道泥沙淤积的动力机制以及泥沙粒度对回淤的指示作用。分析表明，海域来沙为西水道的主要泥沙来源，泥沙运动以“波浪掀沙、潮流输沙”为主要特征；悬沙和底质粒度对比表明，上航道和中航道段航道回淤以悬沙落淤为主，下航道和外航道段航道回淤以底沙推移为主。航道回淤泥沙作为泥沙运动的“指示剂”，能够较好地揭示航道回淤的机理；采用刘家驹悬沙淤积模式和罗肇森底沙输移模式相结合的方法，估算丹东港大东港区20万吨级航道回淤量为679万m3，与物理模型试验结果较为接近，上述分析方法和公式可适用于砂质海岸航道回淤计算，也为类似航道回淤研究提供了重要的参考和借鉴。%Based on the analysis of current velocity,suspended sediment concentration(SSC),and grain size suspended and bed sediments in the west channel of the Yalu River Estuary,the mechanism of sediment hydrodynamics in Dandong Waterway was studied to explore the indication of waterway siltation by grain size distribution. The results showed that the sediment source of the west channel was mainly coming from the adjacent sea area and the sedimentation was characterized by wave lifted sedi-ment and tidal transport sediment. The comparative analysis of the grain size of suspended and surface sediments showed that the suspended sediment deposition was the mechanism of waterway siltation in the upper and middle reaches of the navigation channels,and the bed load transport was the mechanism of waterway siltation in the lower and outer reaches of the navigation channels. Through the analysis of the grain-size characteristics of suspended and surface sediments,channel siltation,being the indicator of sediment movement, can be used to reveal the mechanism of waterway siltation. The back-silting quantity of Dandong Waterway was 6.79í106 m3 calculated with Liu Jiaju’s and Luo zhaosen’s models, which was close to the results of physical model test. Above analysis of the silting mechanism and estimation method provided the important reference of water-way siltation research in sandy beach.
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