小市航运枢纽工程库区泥沙淤积及回水分析

Sediment siltation and backwater in reservoir area of Xiaoshi shipping hub project

小市枢纽为沱江流域最后一梯级。依据李家湾(富顺)水文站泥沙资料进行库区泥沙淤积分析计算,基于现有资料进行河床演变分析并对淤积成因进行研究,采用一维水动力计算模型分别计算受长江顶托和不受顶托两种工况的建库前后水面线。结果表明,个别断面淤积现象较严重;河槽有冲有淤,整体形态基本稳定;受顶托工况下的水面比降明显小于天然情况下的水面比降,受洪水顶托的影响在坝前明显比库尾小。

The Xiaoshi shipping hub is the last step of the Tuojiang River Basin. According to sediment data from Lijiawan(Fushun) hydrological station, this paper calculates and analyzes the sediment deposition in the reservoir area. Based on the existing data, the paper studies the riverbed evolution and the causes of deposition and uses a one-dimensional hydrodynamic calculation model to calculate water surface lines before and after reservoir construction, with the backwater effect of the Yangtze River being absent or present. The results show that the deposition phenomenon of some cross sections is serious. The channel is scoured and silted, and its shape form is basically stable. The water surface slope under the backwater effect is significantly less than that under natural conditions, and the impact of the flood backwater effect is significantly smaller in front of the dam than the tail of the dam.