闽江下游感潮河道枯水动力特性变化分析

建立了闽江下游河道一维非恒定流数学模型,对枯水大潮条件下闽江下游河道沿程各断面的潮位、流量变化过程进行了模拟;结合历史实测资料,对闽江下游河道枯水条件下水动力特性及其变化进行了分析。结果表明,闽江下游河道潮区界、潮流界上溯明显,南北港涨潮流规律有所不同,南港分流比达30%左右,回复到1985年前水平,而干流及南北港河道河床严重下切是枯水动力条件变化的主要原因。

Study on variation of hydrodynamic characteristics during dry season in the lower reach of Minjiang River

Based on the Saint-Venant equations,one-dimensional hydrodynamic model for the lower reach of Minjiang River is set up.Applying the verified model,the process of tide levels and discharges of spring tide during dry season is numerically simulated,and the variation of hydrodynamic characteristics in the lower reach is analyzed accordingly with the comparison of the historical data.It shows that the tidal limit reach upward obviously,the rule of the flood tide in the South Channel differs from that of North,and the flow diversion ratio between South and North Channel has reverted to the level before 1985.Finally,it is analyzed that the descending of the riverbed of the mainstream and the South and North Channel is the main cause of the great change on the hydrodynamic characteristics during dry season.