瓯江口海域悬浮泥沙输运特性研究

Study on characteristics of suspended sediment transport in Oujiang river estuary

基于无结构网格海洋模型,建立了瓯江口三维潮流和泥沙数学模型。模型水平方向采用三角形网格,使得能够更好地拟合瓯江口外众多岛屿和复杂曲折的不规则岸线边界,垂向采用σ坐标。模型计算结果与实测结果吻合良好,较好地模拟了瓯江口潮流场和悬沙场的时空分布。运用通量机制分解的方法,通过三维水体长期输运速度和悬沙输运速度来分析瓯江口的悬沙输运特性,表明瓯江口内主要受控于潮汐作用,泥沙向陆输运。

A three-dimensional tidal flow and sediment model of the Oujiang river estuary was developed in the frame of an unstructured grid ocean model.To better fit the numerous islands outside this estuary and the complex irregular coastline boundary,triangular elements was adopted for the horizontal plane and σ-coordinate in the vertical direction.The results reveal that the simulated values agree well with the observations,and they well describe the spatial and temporal variations of the tidal flow and suspended sediment in the estuary.This paper presents an analysis of the characteristics of suspended sediment transport in the estuary that uses a method of flux decomposition and the calculated velocity data of long-term water and suspended sediment transport.Results show the tendency of sediment transport from the sea into the estuary under predominant tidal action.