三峡工程运用后武汉段河道冲淤变化研究

Erosion-Deposit Variation of the Channel in Wuhan Reach After the Operation of TGP

三峡工程建成运用后,改变了水库下游河道的水沙条件,坝下游河道水流输沙能力处于不饱和状态,河道将发生沿程冲刷,并可能影响武汉河段的河势调整,进而可能对防洪产生一定影响。为此,在三峡大坝下游一维水沙数学模型最新计算成果基础上,采用数学模型计算与实测资料分析的手段进行了三峡工程建成后武汉河段水沙变化及河道冲淤演变研究。结果表明:三峡工程运用50年武汉河段河势没有发生大的变化,深泓线总体没有发生大的调整,白沙洲仍保持两汊过流的趋势,天兴洲左汊持续衰退,右汊发展。

The completion of the Three Gorges Project has changed the conditions of water and sediment in the downstream channel of the Three Gorges reservoir.Sediment transport capacity of the channel is in an unsaturated state.As a result,riverbed scouring will take place along the river channel,which may bring about adjustment of the Wuhan river regime and may further impact the flood control.In view of this,based on the latest research result of one-dimensional sediment mathematic model,the mathematic model computation along with the observed data analysis is used to conduct preliminary researches on the variation of sediment and the erosion-deposit evolution of the river channel in Wuhan river regime.The research result shows that after a 50-year operation of the Three Gorges Reservoir,there is little change of the river regime and the thalweg of the Wuhan reach.The two branches of Baisha sandbar are kept flowing.However,the left branch of Tianxing sandbar continues to decline,while with the right branch growing.