三峡水库运用后荆江河道断面形态变化及对航道条件的影响

利用三峡水库运用后水沙、地形资料,分析了荆江河道水沙、河道冲淤、宽深比、断面形态变化的规律,并在此基础上研究了断面形态变化对荆江航道条件的影响.结果表明:三峡水库运用后荆江不同类型河道断面形态呈现不同的变化规律,同时也存在共同特点,即上游水沙条件变化引起边滩冲刷,河宽增加,束水能力下降,同流量下河道水流弯曲度有所减小；受长期清水下泄的影响,以上变化将会进一步持续和发展,边滩冲刷、河宽增加仍将是未来一段时期荆江特别是下荆江河道变化的主要形式和特征,这些变化将对荆江的航道条件产生一定的不利影响.

Morphology variation of different sections in Jingjiang river and its impact on Jingjiang channel condition after TGR operation

This paper utilizes the data of water and sediment and river topography after the impoundment of the Three Gorges reservoir to analyze the channel and sediment of Jingjiang river, channel scouring and siltation,width-to-depth ratio and change of riverbed profile. On this base, this thesis studies the impact of the change riverbed profile on the Jingjiang channel condition. The laws of morphology variation of different sections in Jingjiang river are proved to be different after TGR operation, yet common features among these laws are clearly represented by upstream water sediment variation-deduced point bar scouring, river-width expansion, and contraction decline,as well as the decrease of degree of curve under the same flow. Under the impact of release of water these changes will be sustainable development. The nearshore scouring and the width of river channel increase are still themain forms and features. Moreover, these changes may bring about some unfavorable effects on Jingjiang channel condition.