长江下游江心洲与江岸并接的一个实例

A real example of mid-stream island combined with river bank inthe Lower Changjiang river

长江下游干流河道的历史演变资料表明，江心洲与江岸的并接，是本河段河床演变的主要模式之一．本文根据实测资料，分析了安庆市宿松县上三号洲近期左汊的淤积过程，认识到：进汊主流在汛枯期的周期往复摆动、及分汊前泥沙的单向横向输移，导致支汊的逐年淤积．是江心洲与江岸并接的主要机理．而人为的适时堵汊，则使这一过程得以最终完成．

The lower reach of the Changjiang River is known as a typical branched river pattern Thehistorical records showed that the midstream island combined with river bank was one of themain process of the river bed evolution in this reach In recent years,the left branch of the Upper Sanhow Island near Anching city.Anhui province was siltting obviously and a descriptionabout the process of deposition has been made in this paper according to the field observed data.Through a preliminary analysis.It is recognized that the deposition process of a branchedchannel is the result of mutual action of the reach boundary. flow movement and suspended sediment transportation:(1)In a gradually widened reach. the deposit of suspended sediment is unavailable,while the narrow nodes located at the down stream makes the sharply accumulated deposite.(2)The alternative of inlet makes and maintains a bifurcated river reach.(3)While abranched channel is deposited.the transverse sediment deliverance in the front of island is indispensable.Finally,the author suggest that adopting a man-made works to choke up the depositting branch is advisable.