群岛阻滞效应影响舟山群岛水流挟沙力空间变化研究

Spacial distribution of sediment carrying capacity caused by retarding effect of Zhoushan Archipelago

在舟山群岛海域大范围实测资料的基础上,通过分析指出舟山群岛海域的含沙量空间分布具有明显的东南方向低、西北方向高的特点。同时,利用平面二维潮流及波浪数学模型模拟该海域的潮流场和波浪场,在此基础上对比刘家驹、窦国仁公式、不分区及分区拟合的挟沙力公式的计算结果与实测含沙量的差异,提出群岛水域只有分区计算才能从整体上把握挟沙力的空间分布特性,并从波浪及潮流的角度分析群岛水域水动力条件的变化,提出是群岛的阻滞效应导致了挟沙力空间分布的不均匀性。此外,对刘家驹及窦国仁公式的适应性进行了初步探讨,提出在舟山群岛水域,刘家驹公式中系数0.0273修正为0.13后能获得较为合理的计算结果。

Based on field data in the Zhoushan Archipelago sea area,the distribution of suspended sediment concentration is analyzed.By a 2D tidal current numerical model and a wave transportation numerical model,the tidal current and wave fields were simulated.Moreover,by comparing results of Liujiaju formula,Douguoren formula,non-subarea and subarea best-fit formulas and field data of suspended sediment concentration,it is concluded that the suspended sediment concentration in each subarea of the archipelago sea area should be calculated separately.And then,through analysis of spatial variation of wave and tidal current fields,it is found that the retarding effect of archipelago leads to the asymmetric distribution of sediment carrying capacity.Furthermore,based on the discussion on adaptability of Liujiaju and Douguoren formulas,it is proposed that,in order to get reasonable results,the coefficient of 0.0273 in Liujiaju formula should be modified to 0.13.