| 长江中游动床阻力计算 |
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| 引用本文： | 刘鑫,夏军强,周美蓉,邓珊珊.长江中游动床阻力计算[J].水科学进展,1990,31(4):535-546. |
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| 作者姓名： | 刘鑫 夏军强 周美蓉 邓珊珊 |
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| 作者单位： | 武汉大学水资源与水电工程科学国家重点实验室, 湖北武汉 430072 |
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| 基金项目： | 国家重点研发计划资助项目（2016YFC0402305）；国家自然科学基金资助项目（51725902） |
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| 摘 要： | 动床阻力计算是水沙数学模型中的重要研究内容。三峡工程运用后，进入长江中游河段的沙量剧减引起河床冲刷及床沙粗化，导致动床阻力的变化特点更复杂，有必要研究长江中游动床阻力的计算方法。采用长江中游枝城、沙市及汉口等5个水文站2001—2012年的1 266组实测数据，选取弗劳德数（Fr）和相对水深（h/D50）作为动床阻力计算的主要影响因子，建立基于水流能态分区的动床阻力公式并利用多元非线性回归的方法率定相关参数，采用长江中游上述5个水文站2013—2017年的651组实测数据对公式进行验证。结果表明：① 长江中游的动床阻力主要处于低能态区和过渡区；② 基于水流能态分区动床阻力公式的计算精度明显高于现有阻力公式，决定系数（R2）约为0.89，阻力系数n的计算偏差小于±30%的数据达97.7%。
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| 关 键 词： | 动床阻力 弗劳德数 相对水深 水流能态区 长江中游 |
| 收稿时间： | 2019-11-05 |
Formula of movable bed roughness for the Middle Yangtze River |
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| LIU Xin,XIA Junqiang,ZHOU Meirong,DENG Shanshan.Formula of movable bed roughness for the Middle Yangtze River[J].Advances in Water Science,1990,31(4):535-546. |
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| Authors: | LIU Xin XIA Junqiang ZHOU Meirong DENG Shanshan |
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| Institution: | State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China |
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| Abstract: | The computation of movable bed roughness is an important step in morphodynamic models. After the operation of the Three Gorges Project (TGP),a dramatic decrease of sediment load entering the Middle Yangtze River (MYR) caused the processes of channel degradation and coarsening of bed material,and the variation characteristics of the movable bed roughness became more complicated. Therefore,it is necessary to propose the formula of movable bed roughness for the MYR. Based on the 1 266 runs of measurements at five hydrometric stations such as Zhicheng,Shashi,and Hankou during the period 2001—2012,Froude number (Fr) and relative water depth (h/D50) were selected as the main factors influencing the magnitude of movable bed roughness. Based on the theory of flow regime partition,the formula of movable bed roughness was established and calibrated by these measurements using the method of multiple nonlinear regression. Finally,the predictive accuracy of the proposed formula was verified against 651 runs of independent measurements at those stations from the MYR during the period 2013—2017. The results indicate that:① the alluvial resistances in the MYR are in the lower or transitional flow regime for most of the time;and ② the calculation accuracy of the proposed formula based on the flow regime partition is significantly higher than the existing formulas with the determination coefficient (R2) of 0.89. Moreover,the Manning's roughness coefficients predicted by the new formula have the errors less than ±30% for 97.7% of the measurements. |
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| Keywords: | movable bed roughness Froude number relative water depth flow regimes Middle Yangtze River |
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