杭州湾北岸弧形岸段悬沙净输移分析——以龙泉—南竹港岸段为例

Analysis on the net sediment transportation along arc-shaped coast in the northern bank,Hangzhou bay——a case study of Longquan-Nanzhu harbor segment

基于杭州湾北岸龙泉—南竹港弧形岸段的实测水文泥沙资料,利用余流分析和悬沙机制分解方法对该岸段的悬沙输运变化特征进行分析,并经2004-2005年地形冲淤验证。结果表明:龙泉—南竹弧形岸段的动力条件相对较弱,余流表现为总体向西流动,特征为"两头大、中间小",机制分解得出悬沙输运以净进为主,各动力项中主要以平均流项和stokes漂流项为主,平均输沙率方向受平均流项控制,涨落潮挟沙强度对净输沙也有一定的贡献,并导致研究区西部岸段出现逆向输沙;余流和机制分解结果表明海岸的中部及东部为悬沙的主要落淤地带,而西部则冲刷加深,这与地形的冲淤分析相一致。

Based on the measured data of hydrology and suspended sediment along arc-shaped coast of Longquan-Nanzhu harbor segment in the northern bank of Hangzhou bay,the characteristic of suspended sediment transportation was analyzed by using residual current statistic calculation and the method of mechanism.Moreover,these results were further verified by the analysis of erosion and deposition of topography in different years.The conclusions showed that the condition of dynamic action was weak in the middle of arc-shaped coast of Longquan-Nanzhu harbor segment,where a local circumfluence was formed by the tidal current.The rate of net sediment transportation in the eastern segment was much larger than that in the west segment in this region.In addition,the main deposition zones existed in the central and east sectors.