汉江兴隆枢纽坝下河床冲刷引起的水位变化

Water level changes caused by riverbed erosion under Xinglong Hub of Han River

汉江兴隆枢纽运行以来坝下河床冲刷较为严重,枯水期下游最低通航水位下降幅度较大。为保证兴隆枢纽安全运行,枢纽正常蓄水位需同步降低,以适应坝下水位下降,导致兴隆船闸上下闸首枯水期门槛水深不足,千吨级船舶通航保证率不高。针对兴隆枢纽坝下河床冲刷引起的水位变化问题,通过分析汉江现状水文泥沙特性和枯水水文情势,运用一维与二维长系列年水沙数学模型,滚动计算60 a和50 a兴隆坝下河床冲淤及水位变化情况,得出40 a后坝下同流量对应的水位逐渐趋于稳定,并考虑2000吨级航道整治工程实施后,且汉口站水位每年下降0.1 m情况下,50 a末兴隆坝下水位将可能下降3.77 m,旨在为汉江兴隆枢纽坝下河段相关工程设计水位的确定提供参考。

Since the operation of Xinglong Hub on the Han River,the riverbed under the dam has been severely eroded,and the lowest navigable water level downstream has decreased significantly during the dry season.To ensure the safe operation of Xinglong Hub,the normal water storage level of the Hub needs to be lowered synchronously to adapt to the decrease in water level below the dam,resulting in insufficient threshold water depth for the upper and lower locks of Xinglong Shiplock during the dry season,and low navigation guarantee rate for ships of 1000-ton.In response to the problem of water level changes caused by riverbed erosion under Xinglong Hub Dam,this paper analyzes the current hydrological and sediment characteristics and dry water hydrological situation of the Han River,and uses one-dimensional and two-dimensional long series annual water and sediment mathematical models to rolling calculate the riverbed erosion and sedimentation and water level changes under Xinglong Dam for 60 and 50 years.It is found that the water level corresponding to the same flow rate under the dam gradually stabilized after 40 years,considering the implementation of the 2000-ton waterway regulation project and the annual decrease of 0.1 m in water level at Hankou Station,the water level under Xinglong Hub Dam may decrease by 3.77 m by the end of 50 years.The aim is to provide reference for the determination of the design water level of the relevant engineering projects in the section under Xinglong Dam of the Han River.