三峡上游建库对重庆河段泥沙淤积的影响

通过平面二维水沙数学模型,对三峡上游建库前后重庆河段的泥沙淤积进行了分析。结果表明,上游无库情况下,由于重庆河段在汛后蓄水期水位壅高,挟沙力下降,原有的汛末走沙规律将受到破坏,将造成水库运用初期的累积性淤积。随着水库运行时间的增长,部分浅滩河段将产生碍航问题。上游建库后,由于上游来水挟沙能力富余,在水库蓄水100年内,重庆河段长江干流呈现冲刷趋势,但支流金沙碛河段的淤积情况和上游无库时差别不大。

Impact on Sediment Deposition Along Chongqing Reach Due to Construction of Reservoirs in the Upper Yangtze River

Sediment deposition along Chongqing Reach after the construction of the reservoirs is studied by 2-D flow and sediment model.The result proves that under the condition of no reservoirs in the upper basin,accumulated sediment deposition will increase in the initial period of the use of Three Gorges Reservoir for the elevation of water level and decline of sediment carrying capacity.With the increase of the operation time of the reservoir,navigation obstruction will occur at local shoals.Following the construction of reservoirs in the upper basin,erosion will occur along the main reach of Chongqing within 100 years from the impounding of the Reservoir,but sediment deposition along Jinshaqi reach is similar to that under the condition of no reservoirs in the upper basin.