水系连通机理及其影响因素

为了摸清水系连通性衰退的成因,本文通过引入水系连通性指标和推求河道水力几何关系,深入分析了水系连通性的连通机理和影响因素.结果表明河道纵向连通性取决于河道来水来沙条件与边界形态,侧向连通性取决于河道分汇流比及分汇流区的水流流态和冲淤形态,河道横向连通包括河道滩槽并存、洪水期滩槽水沙交换以及水生植物的传播,主要是通过洪水...

Mechanism and influence factors of water system connectivity

In order to analyze the causes of water system connectivity decline, the connectivity mechanism and influencing factors of water system connectivity were studied in this paper by introducing the connectivity index and deriving the hydraulic geometry relationship of river channel. The results show that the longitudinal connectivity depends on the relationship between the incoming water and sediment conditions and the boundary conditions. The lateral connectivity depends on the river diversion/confluence ratio, the flow pattern and the erosion and deposition pattern of the diversion/confluence area. The transverse connection includes the coexistence of floodplain and main channel, and the exchanges of water and sediment and the spread of water organisms between floodplain and main channel during the flood period,which is mainly realized by the periodic fluctuation of flood. In addition,the main influencing factors of river connectivity are precipitation change in the basin, river regulation and embankment construction, reservoir construction and diversion works. In a word, the internal mechanism and control relationship of water system connectivity is the coordination among the incoming water & sediment conditions, diversion (confluence) condition and the boundary condition.