乌龙江峡兜卡口阻力特性及壅水效应分析

峡兜卡口是乌龙江最为重要的控制断面,其阻力特性及其对乌龙江洪水位及行洪能力的影响尚不明确。采用二维数学模型计算了不同洪水方案下乌龙江峡兜卡口水面线、水面比降及流速分布特征,对产生壅水的临界流量、壅水高度及作用范围进行了分析。结果表明:峡兜卡口是乌龙江河道水面比降最大的位置,在峡兜流量超过19320 m^3/s后是乌龙江河道断面平均流速最大的位置,其阻力特性和壅水效应与流量密切相关;初步认定峡兜卡口发挥壅水作用的临界流量为19320 m^3/s,在峡兜流量为35037 m^3/s(P=0.5%)、32333 m^3/s(P=1%)、29435 m^3/s(P=2%)时,峡兜壅水高度分别为0.13、0.10、0.07 m,壅水影响范围可分别至峡兜上游1.99、1.88、1.69 km。

Analysis of resistance characteristics and backwater effect of Xiadou Bottle-neck of the Wulongjiang River

The Xiadou bottle-neck is the most important control section of the Wulongjiang River.Its resistance characteristics and backwater effect on the flood level and flooding capacity of the Wulongjiang River are still unclear.A two-dimensional mathematical model was used to calculate the water surface profile,water surface slope and velocity distribution characteristics of the Wulongjiang River under different flood computational schemes,and the critical flow rate,the height and reach of backwater of Xiadou bottle-neck were analyzed.The results showed that the Xiadou bottle-neck has the maximum slope of water surface of the Wulongjiang River.When the flow rate of the Xiadou bottle-neck exceeds 19320 m^3/s,the maximum average velocity of Wulongjiang River is located in the Xiadou bottle-neck,and its resistance characteristic and backwater effect are closely related to flow.It is preliminarily determined that the critical flow rate of the Xiadou bottle-neck is 19320 m^3/s.When the flow rate of Xiadou is 35037 m^3/s(P=0.5%),32333 m^3/s(P=1%),29435 m^3/s(P=2%),the height of the backwater is 0.13 m,0.10 m,0.07 m,respectively.And the reach of the backwater located up to 1.99 km,1.88 km,1.69 km upstream of Xiadou bottle-neck.