孙昭华, 周歆玥, 范杰玮, 熊海滨, 谈广鸣. 考虑回水影响的河道水位流量关系确定方法[J]. 水科学进展, 2021, 32(2): 259-270. DOI: 10.14042/j.cnki.32.1309.2021.02.011
引用本文: 孙昭华, 周歆玥, 范杰玮, 熊海滨, 谈广鸣. 考虑回水影响的河道水位流量关系确定方法[J]. 水科学进展, 2021, 32(2): 259-270. DOI: 10.14042/j.cnki.32.1309.2021.02.011
SUN Zhaohua, ZHOU Xinyue, FAN Jiewei, XIONG Haibin, TAN Guangming. Stage—discharge rating method considering backwater effect in river channel[J]. Advances in Water Science, 2021, 32(2): 259-270. DOI: 10.14042/j.cnki.32.1309.2021.02.011
Citation: SUN Zhaohua, ZHOU Xinyue, FAN Jiewei, XIONG Haibin, TAN Guangming. Stage—discharge rating method considering backwater effect in river channel[J]. Advances in Water Science, 2021, 32(2): 259-270. DOI: 10.14042/j.cnki.32.1309.2021.02.011

考虑回水影响的河道水位流量关系确定方法

Stage—discharge rating method considering backwater effect in river channel

  • 摘要: 为评估长江中游受回水影响河段内河床调整引起的水位变幅,提出一种仅依赖水文资料的多值型水位—流量关系确定方法。结果表明:单值型关系无法区分河床调整与回水因素的影响,而已有的多值型方法可操作性受限;长江中游河道断面的河宽与水深之间,以及流量与糙率之间都具有明显制约关系,依据这些制约关系对恒定渐变流方程简化,可得到上下游水位与河段内流量之间的多值型函数关系;确定出多年平均水位—流量关系之后,计算水位与实测水位之间的残差能够反映河床调整的影响;在长江中游3个不同类型典型河段的应用表明,河床稳定情况下的计算与实测水位之间决定系数R2值超过0.99,河床调整情况下,新方法更易识别水位变幅。

     

    Abstract: To quantify stage variations in the middle reaches of the Yangtze River that are affected by backwater effect and channel adjustments, the hydraulic characteristics of selected typical reaches were analyzed and the applicability of previous stage-discharge rating methods was studied. Furthermore, a hydrological data-based stage-discharge rating method for non-uniform flow was proposed. Results indicated that the influences of channel adjustments and backwater effect cannot be separated using stage-discharge rating methods for uniform flow. Moreover, previous rating methods for non-uniform flow were difficult to use when only stage, but not discharge, should be estimated. Although channel morphology is irregular in the middle reaches of the Yangtze River and the flow roughness coefficient varies at different discharges, evident laws for channel hydraulic geometry factors and roughness-discharge relation were observed. The momentum equation for steady non-uniform flow can be simplified on the basis of the hydraulic features of the channel to obtain the rating function between the upstream and downstream stages and discharge. By using the proposed rating method, the upstream stage can be estimated via the rating function based on long term data. Meanwhile, the residuals between the estimated and measured stages represent the effects of channel adjustments. Lastly, the proposed method was applied to three typical reaches to examine its accuracy and applicability. The results showed that the coefficient of determination (R2) between the measured and estimated stages exceeded 0.99 when the channel was not altered. Therefore, the proposed method is capable of identifying stage changes caused by channel adjustments.

     

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