水库变动回水区分汊河道河型转化影响因素分析  

Analysis of influences on river pattern change of braided channel in reservoir fluctuated backwater area

作　　者：赵瑾琼[1] 

机构地区：[1]长江科学院河流研究所,湖北武汉430010

出　　处：《人民长江》2013年第17期52-55,共4页Yangtze River

基　　金：国家自然科学基金青年基金项目(51209018);国家科技支撑计划课题(2012BAB04B02)

摘　　要：分汊型河道向单一河槽转化是水库变动回水区中一种较为普遍的淤积再造床过程。以三峡水库变动回水区青岩子河段为研究对象,运用平面二维水沙数学模型,分析来沙量、壅水高度等因素对主支汊易位、河型转化的影响。研究结果表明,来沙量减少并未改变泥沙落淤部位和河床演变趋势,虽然同期淤积数量和范围缩小,但河型转化仍将发生;相同水沙条件下,主支汊易位受壅水高度与河床周界条件的双重制约,水位壅高越多,水流动力轴线的变化越明显,泥沙落淤增多,地形条件改变;河床周界条件的变化又反作用于水流流态,从而进一步加速河床形态的调整。The transformation of braided channel to single channel is a common process of deposition and river deformation in reservoir backwater area. The influences of incoming sediment, backwater height, etc. on transloeation of main and branch channels, river pattern change of Qingyanzi reach, a fluctuated backwater zone of Three Gorges Reservoir, are analyzed by 2D flow and sediment mathematical model. The analysis results show that the reduction of incoming sediment does not change the deposition location and river bed evolution tendency, though the deposition amount and scope reduce in the same period, the river pattern will still change; under the same flow and sediment condition, the change of the main channel and branch channel is influenced by 2 factors of the backwater height and the boundary condition of river bed, the higher the backwater, the more obvious variation of flow axis, and more deposition of sediment can change the landform condition; the variation of boundary condition of river bed conversely influences the flow pattern and accelerates the adjustment of river morphology.

关 键 词：河型转化 变动回水区 泥沙淤积 分汊河道 

分 类 号：TV147[水利工程—水力学及河流动力学]