摘要
在分析黄河小北干流和渭河下游河道淤积的主要影响因素和演变机制的基础上,将河道淤积体纵剖面的平衡形态概化为一个由潼关高程抬升值ΔZ、初始河床比降J0和平衡比降Je所决定的三角形,得到了河道初始形态与平衡形态之间淤积体的体积计算公式,进而基于河床演变的滞后响应模型,建立了既能考虑河床调整的滞后响应特性又能考虑潼关高程和水沙条件协同作用的黄河小北干流和渭河下游河道淤积量的计算方法。采用1960—2001年黄河小北干流和渭河下游河道长系列冲淤资料对计算方法中的参数进行了率定,并采用2002—2010年实测河道冲淤资料进行了检验,结果表明,建立的计算方法能够较为全面地反映河床调整的驱动机制和内在机理,模拟计算及预报精度较以往方法有较大提高。结果还显示潼关高程对两河道的长期累计淤积过程的影响占主导地位,在1960—2011年实际水沙条件下,潼关高程每下降1m,小北干流和渭河下游累计淤积量分别减少约5.1亿m3和2.7亿m3;近期潼关高程和水沙条件对河道的淤积均具有重要影响,二者对2003年水库采用318m控制运用以来产生的河道减淤量的贡献约各占一半,体现了潼关高程和水沙条件的协同作用。
Based on the analysis of the impact factors and the mechanisms of the fluvial processes of the Xiaobeiganliu reach of the Yellow River and the lower Wei River （LWR）,it’s assumed that the channels reach in their potential equilibrium states,compared to the initial boundaries,have a deposition body with a triangular longitudinal shape determined by the variation of Tongguan elevation ΔZ, initial channel bed slope J0 and the potential equilibrium slope Je. Using the delayed response model and an equation devel-oped for calculating the volume of triangular deposition body,a method for simulating the deposition process-es of the river reaches has been proposed. The coefficients in the method were determined using the data during 1960 and 2001,and the applicability of the method was verified using data during 2002 and 2011. The results show that the method takes into account the effects of both Tongguan elevation and water and sediment conditions,and it better reflects the mechanism of channel adjustment and has higher calculation accuracy than previous methods which consider only the impact of Tongguan elevation on channel aggrada-tion and degradation. In addition,based on the actual incoming water and sediment volumes during 1960 and 2011,it’s estimated that the accumulated sediment deposition volumes of the Xiaobeiganliu and LWR will decrease some 0.51 and 0.27 billion m3 on average with Tongguan elevation lowering by every 1 m. It’s indi-cated that the Tongguan elevation had main influence over the long-term evolution of the channel reaches, while the lowing of Tongguan elevation and the favorable water and sediment conditions have played fairly the same important roles in the channels’ degradation since 2003 when an operation scheme of Sanmenxia Reservoir was initiated to prevent the pool level from exceeding 318 m during non-flood seasons. The com-bined impacts of Tongguan elevation and income water and sediment conditions on the recent adjustment of the river reaches are obvious.
出处
《水利学报》
EI
CSCD
北大核心
2014年第2期150-162,共13页
Journal of Hydraulic Engineering
基金
国家"十二五"科技支撑计划课题(2012BAB02B02)
国家重点基础研究发展计划课题(2011CB403304)
水沙科学与水利水电工程国家重点实验室开放研究基金资助课题(sklhse-2014-B-02)
关键词
黄河小北干流
渭河下游
潼关高程
水沙变化
淤积
滞后响应模型
Xiaobeiganliu
Lower Weihe River
Tongguan elevation
water discharge and sediment load
channel aggradation
delayed response model
