摘要
内湖与长江直接相通,在径流与潮流双重作用下,其水量、悬沙交换规律复杂多变。本文建立了内湖二维水流-悬沙耦合数学模型,在有限体积法框架下应用通量差分裂(FDS)格式计算模型中各跨单元边界的数值通量,基于内湖野外同步监测数据对模型进行了率定验证;选择典型年及典型潮汐过程,对不同时间尺度下内湖与长江水沙交换过程进行数值计算,结果表明:内湖水流通量、悬沙沉积量年际、年内分布较不均匀,丰水年内湖水流通量及悬沙沉积量明显高于平水年、枯水年;各典型年内,水沙交换量主要集中在洪季5月至10月,洪季水流通量与悬沙沉积量分别约占全年总量的90%与95%;内湖洪季全日潮水流通量约8292.3万m3,悬沙沉积量约1 344.1t,明显高于枯季;潮汐作用对内湖水沙交换影响较大,在全潮最低水位时刻,内湖水流通量最小但悬沙沉积量却达到最大。
The Inner Lake in Zhenjiang City is connected with the Yangtze River directly. Due to the double impact of runoff and tide, the transformation principles of dynamic condition and suspended sediments in the Inner Lake are very complex. A 2-D unsteady hydrodynamic-sediment model for the Inner Lake was established. The finite volume method and the flux difference splitting （FDS） scheme were employed to calculate the numerical flux across the interface between cells. Parameters of the model were calibrated and validated using the field investigated data. The exchanging process of flow and sediment between the Inner Lake and the Yangtze River in different years and different tidal cycles were simulated by the established model. The calculated results indicated that the amount of flow flux and sedimentation were asymmetrical distributed in different years and seasons. The amount of flow flux and sedimentation in high-water year were obviously more than those in common-water year and low-water year. The amount of flow flux and sedimentation were mainly concentrated in flood season from May to October. The proportions of the amount of flow flux and sedimentation in flood seasons to the annual quantity take 90 % and 95 % respectively. The amounts of flow flux and sedimentation during a tidal cycle in a flood season, are 8.29 ×10^7 m^3 and 1344.1t respectively, which are much more than those in dry season. The flow and sediment exchanging processes between the Inner Lake and the Yangtze River were greatly influenced by tides. At the neap time, the flow flux of the Inner Lake reached the lowest, whereas the amount of sedimantation went to the maximum.
出处
《泥沙研究》
CSCD
北大核心
2009年第5期29-34,共6页
Journal of Sediment Research
基金
国家自然科学基金(50579015)
国家863"十五"重大科技专项(2003AA6011002)
关键词
内湖
长江
水流通量
悬沙沉积
交换
the Inner Lake
the Yangtze River
flow flux
sedimentation
exchange
