三峡水库蓄水后铜陵河段演变特点及趋势分析

长江下游铜陵河段为典型的鹅头型多汊河道，通过对三峡水库蓄水前后该河段水沙特性、深泓线、平面形态和断面冲淤变化的分析，结论表明，受三峡水库运行和上游水土保持工程的影响，该河段上游的大通站来沙量大幅减少，河段内各汊道发生相应的调整。其中成德洲右汊和南夹江汊道冲刷发展，成德洲左汊进口有所淤积，造成成德洲右汊和南夹江汊道分流比逐渐增大，对南夹江的防洪造成不利影响。建议采取适当的治理措施，防止河势向不利防洪和航运方向进一步发展。

Evalution characteristics and trends of Tongling reach after impoundment of Three Gorges Reservoir

Tongling reach is a typical goose-head pattern braided channel of the middle and lower Yangtze River,through analysis on flow and sediment characteristics,talweg,morphology and sectional scouring and deposition of the reach before and after impoundment of the Three Gorges Reservoir,the conclusions are achieved as follows: affected by the Three Gorges Reservoir and upstream soil and water conservation projects,the incoming sediment amounts at Datong station of Tongling reach decreases greatly,and each braided channel varies correspondingly;the right branch of Chengde island and Nanjiajiang branch are scoured,but the inlet of left branch of Chengde island is silted,leading to gradual increase of the diversion radio of the right branch of Chengde island and Nanjiajiang branch,and exerting negative impacts on flood control of Nanjiajiang.It is suggested that appropriate control measures should be taken to prevent the negative impacts on flood control and navigation.