感潮河网区分汊河道险段成因试验研究  

Experimental Study on Formation Mechanism of Branching River Pitch in Tidal River Network

作　　者：何用 张金明 何贞俊 

机构地区：[1]珠江水利委员会珠江水利科学研究院,广东广州510611 [2]水利部珠江河口动力学及伴生过程调控重点实验室,广东广州510611

出　　处：《水电能源科学》2015年第10期92-96,共5页Water Resources and Power

摘　　要：针对珠江三角洲受径潮动力双重作用、感潮河网区分汊河道险段成因较单一河道复杂的问题,选择典型分汊型险段,以动床物理模型试验为研究手段,在分析险段近期河床演变规律的基础上,研究了不同水文条件下分汊河道险段水动力特性和冲淤变化规律,探讨了险段变化成因。结果表明,分汊河道险段所在弯道水流特性明显,主流贴岸,易产生近岸冲刷,加之近期大洪水频发,是造成险段冲刷加剧的主要原因,而近期汊点分流变化,险段所在主干分流增强,加剧了险段冲刷;此外,感潮河网区受涨潮动力影响,枯水期支汊涨潮流顶托主汊,汊口水流动力减弱,有利于减缓汊口段险段的冲刷。As the role of tidal power,the causes of branching river pitch in the Pearl River Delta are more complex than that of single channel.Typical pitch branching in the Pearl River Delta was chosen as an example.With movable bed physical model test as the research method,based on the analysis of the pitch recent law of riverbed evolution,hydrodynamic characteristics and scouring and silting in pitch branching channel were studied under different hydrological conditions.And then the change causes of the pitch were discussed.The results show that the bend flow characteristics of the braided river channel pitch is obvious;the primary flow is close to the shore,and it is prone to scour offshore.Combined with the recent flood frequency,these are the main causes for intensifying pitch scour.The recent branch point distribution changes,the distributary of the main channel pitch is strengthened and it intensified the pitch scour.In addition,as the influence of tidal power on the tidal river network area,branch flood jacked the main branch during dry season,flow dynamics in branch mouth is weakened,which helps slow down the erosion of pitch in the branch mouth.

关 键 词：感潮河网 分汊河道 径潮动力 动床模型试验 险段成因 

分 类 号：TV853[水利工程—水利水电工程]