长江宜昌至汉口河段输沙特性分析

Sediment transport characteristics of Yangtze River in river section from Yichang to Hankou

通过对长江宜昌至汉口干支流水文站50年水文资料的分析发现,长江干流年水量变化不大,而年沙量变化很大,造成沙量增减变化的主要原因是荆江三口(藕池口,松枝口,太平口)分洪分沙、量的逐年减少、干流来沙及汉江丹江口水库蓄水运用引起的。本文还从沙量平衡法和断面法分析了宜昌至汉口河段的泥沙冲淤和输沙特性,发现城陵矶至汉口河段长期处于淤积状态,是上下游河段挟沙力平衡的一个调节河段。并预测三峡水库蓄水后下游年沙量将进一步减少。

The characteristics of sediment transport in river section from Yichang to Hankou of Yangtze River are analyzed according to the hydrological data. It is found that the variation of Yangtze River's annual runoff in the period of latest 50 years is not significant but the variation of annual sediment transport is remarkable. This variation is due to three causes: the reduction of coming sediment, the application of flood detention area and the operation of Danjiangkou Reservoir. The river section from Chenglingji to Hankou is always in the state of silting playing a role of regulating the balance of sediment transportation in the whole river section. This result is helpful for predicting the effect of reservoir impounding of Three Gorges Project on downstream reaches.