| 引用本文: | 柳明洋,李春光,赵文娟,等.连续弯道中河心洲可侵蚀层对水动力的影响分析[J].灌溉排水学报,2022,41(12):107-113. |
| LIU Mingyang,LI Chunguang,ZHAO Wenjuan,et al.连续弯道中河心洲可侵蚀层对水动力的影响分析[J].灌溉排水学报,2022,41(12):107-113. |
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| 摘要: |
| 【目的】揭示连续弯道中泥沙侵蚀对河流水动力的影响。【方法】基于二维平均深度浅水方程建立河床侵蚀数学模型，利用MIKE 21模拟了黄河宁夏永丰渡口若干河心洲的连续弯道中的水流流速与水深变化过程。【结果】黄河宁夏永丰渡口在3 h流量为1 545 m3/s条件下，典型断面处的侵蚀模式相比无侵蚀模式的流速差降低0.06~0.27 m/s，水深差降低0.02~0.32 m，侵蚀会导致水深和流速更加平稳；3 h丰水期河床侵蚀深度最大可达0.16 m，最大淤积厚度可达0.12 m；6 h河床侵蚀深度最大可达0.24 m，最大淤积厚度可达0.23 m。随着流量和侵蚀时间的增加，河床演变趋势没有改变，河床侵蚀深度和淤积厚度有所变化。【结论】侵蚀会增大水动力条件的稳定性，河床演变的形态不会随流量的大小而改变，本研究可为河床治理工作提供参考。 |
| 关键词: 黄河；泥沙；河床侵蚀；连续弯道；数值模拟 |
| DOI：10.13522/j.cnki.ggps.2021634 |
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| Hydrodynamic Flow and Sediment Transport in Bended River with the Presence of Islands |
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LIU Mingyang, LI Chunguang, ZHAO Wenjuan, LYU Suiju, QIAO Qiao
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1. Ningxia University, Yinchuan 750021, China; 2. North Minzu University, Yinchuan 750021, China
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| Abstract: |
| 【Objective】 Some rivers have islands. Their soil composition and geometrical shape influence water flow and sediment transport in the rivers. The purpose of this paper is to study the impact of flow rate and flowing duration on sediment erosion and hydrodynamic flow in a bended river. 【Method】The study is based on two-dimensional average shallow water flow and sediment transport over riverbeds. Both water flow and sediment transport are solved using the MIKE 21. The model is applied to the section of Yellow River at Yongfeng Ferry in Ningxia province, where there are several small islands.【Result】When water flows for 3 hours at rate of 1 545 m3/s, sediment erosion reduces water velocity by 0.06~0.27 m/s and water depth by 0.02~0.32 m, compared with the results calculated without considering sediment erosion. Continuous erosion tends to stabilize water depth and flow rate. The deepest erosion depth is 0.16 m after water flows for 3 hours at rate 1 545 m3/s, and this increases to 0.24 m after the flow is increased to 6 hours at the same rate; their associated maximum deposition depth is 0.12 m and 0.23 m respectively. With the increase in flow rate and flow duration, the riverbed stabilizes, though erosion depth and deposition thickness continue to change. 【Conclusion】 Sediment erosion increases the stability of hydrodynamic flow in the river, and the riverbed morphology does not change after flow rate exceeds a critical rate. These simulated results are consistent and can be used to help improve river management. |
| Key words: Yellow River; sediment; riverbed erosion; continuous bend; numerical simulation |
