| 摘要: |
| 自黄河小浪底水库蓄水运用并调水调沙以来，下游游荡段河床持续冲刷，输沙与冲刷效率显著下降。如何科学构建黄河下游游荡段持续冲刷期间输沙与冲刷效率调整的计算方法，就成为后续开展调水调沙重点关注的一个问题。考虑到实测输沙率测量误差对河床冲淤计算的影响，可以花园口进口站实测输沙率为基础，通过模型计算高村出口站输沙率，以达到部分修正高村出口站实测输沙率的目的。基于河床滞后响应模型与沙量平衡法，结合黄河下游输沙计算幂律函数公式，推导建立了考虑河床冲淤过程中输沙系数调整的输沙率滞后响应模型，并应用于游荡段在2000-2022年持续冲刷期间输沙与冲刷效率调整过程的模拟。结果表明，对于游荡段在小浪底水库蓄水运用与调水调沙前后高村出口站输沙率与河床累计冲淤量的变化过程，模拟效果良好，确定性系数R2分别为0.936、0.893，Nash-Sutcliffe效率系数NSE分别为0.93、0.78，相对误差RE分别为-0.03、-0.10；对于游荡段在持续冲刷期间冲刷效率的调整过程，相比实测沙量平衡法计算结果，模拟结果与断面法实测冲刷效率变化趋势更为符合。这表明通过该模型计算可以在一定程度上减少高村出口站实测输沙率存在误差的影响。 |
| 关键词: 黄河下游 游荡段 持续冲刷 输沙调整 冲刷效率 |
| DOI： |
| 分类号:TV142 |
| 基金项目:国家自然科学基金联合基金资助项目(U22A20237)；水利部黄河流域水治理与水安全重点实验室(筹)研究基金资助(2023-SYSJJ-08) |
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| Simulation for the adjustment process of sediment transport and erosion efficiency during continuous erosion period in the braided reach of Lower Yellow River |
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SUI Yingchun1, SHEN Hongbin2, WANG H Z2, CAO Bing1
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1.Dongying Water Authority;2.North China University of Water Resources and Electric Power
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| Abstract: |
| Since the operation and water-sediment regulation of Xiaolangdi Reservoir, the sediment transport and erosion efficiency decreases due to the continuous erosion in the braided reach of Lower Yellow River. How to simulate the adjustment process of sediment transport and erosion efficiency during continuous erosion period in the braided reach is an important question for follow-up water-sediment regulation. Considering the measured errors impact of sediment transport rate on riverbed deformation calculation, it is proposed that the sediment transport rate of Gaocun outlet station can be calculated through a model based on the measured sediment transport rate of Huayuankou inlet station, in order to partially correct the measured sediment transport rate of Gaocun outlet station. Based on the delayed response model for fluvial processes and sediment balance equation, using the power law formula for sediment transport, a delayed response model for sediment transport rate considering the adjustment of sediment transport coefficient during the process of river-bed erosion and deposition is established and applied in the simulation for the adjustment process of sediment transport and erosion efficiency in continuous erosion period from 2000 to 2022 for the braided reach in the Lower Yellow River after the operation of Xiaolangdi Reservoir and water and sediment regulation. The model application results show that the simulation effects for the sediment transport rate of Gaocun outlet station and accumulated erosion and sedimentation volume are good, with the values of determination coefficient are 0.936 and 0.893, the values of Nash-Sutcliffe efficiency are 0.93 and 0.78, and the values of relative error are -0.03 and -0.10. For the adjustment process of erosion efficiency in the continuous erosion period, compared with the calculation results using sediment discharge method, the simulation results are more in agreement with the calculation results using the cross-section method. It indicates that the calculated sediment transport rate of Gaocun outlet station used the proposed model can reduce the error of the measured values at some extents. |
| Key words: the Lower Yellow River braided reach continuous erosion sediment transport adjustment erosion efficiency |
