洮河异重流倒灌对刘家峡库区河床变化的影响
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摘要
刘家峡库区黄河支流洮河为多沙河流,入汇黄河后形成异重流向上游倒灌,使洮河口至黄9断面形成倒比降,对库区河床变化及淤积形态产生较大影响,常规一维数学模型不能反映洮河异重流倒灌对河床变化的影响。根据能量方程结合谢才公式,提出了异重流侧向潜入后倒灌流量的计算方法,构建了包含异重流模块的一维非恒定流水沙数学模型,采用1982—2013年实测资料对刘家峡库区进行了冲淤计算。结果表明:计算结果与实际吻合较好,库区黄河各河段淤积分配计算结果与断面法实测结果基本一致,较好地模拟了黄4断面的淤高及黄河干流淤积三角洲向坝前的推进;洮河异重流倒灌对刘家峡库区黄4—黄9库段河床冲淤变化影响极为明显,计算过程中必须考虑异重流倒灌问题。
As a branch of Liujiaxia Reservoir area,the Taohe River is a heavily sediment laden river. After flowing into the Yellow River,the density current is formed and extended towards the Yellow River upstream and the Taohe estuary bottom is higher than that of Cross Section 9 of the Yellow River. The normal 1D flow mathematical model can not reflect the influence of the density current on the river bed.Based on the energy equation and Chezy Formula,the discharge computing method of density current lateral movement was proposed. The density current calculation module was added into 1D unsteady flow and sediment mathematical models,the Liujiaxia Reservoir river bed variation was simulated. According to 1982-2013 actual measurement records of water flow and sediment,the sediment deposition simulated result of each part was agreed well with the actual records. The simulated result shows the bottom of Cross Section 4 is raised and the Yellow River deposition moved towards the dam. The density current of Taohe River has significant influence to the river beds between cross sections4 and 9 of the Yellow River.
As a branch of Liujiaxia Reservoir area,the Taohe River is a heavily sediment laden river. After flowing into the Yellow River,the density current is formed and extended towards the Yellow River upstream and the Taohe estuary bottom is higher than that of Cross Section 9 of the Yellow River. The normal 1D flow mathematical model can not reflect the influence of the density current on the river bed.Based on the energy equation and Chezy Formula,the discharge computing method of density current lateral movement was proposed. The density current calculation module was added into 1D unsteady flow and sediment mathematical models,the Liujiaxia Reservoir river bed variation was simulated. According to 1982-2013 actual measurement records of water flow and sediment,the sediment deposition simulated result of each part was agreed well with the actual records. The simulated result shows the bottom of Cross Section 4 is raised and the Yellow River deposition moved towards the dam. The density current of Taohe River has significant influence to the river beds between cross sections4 and 9 of the Yellow River.
引文
[1]毛继新,黄永健.刘家峡水库洮河异重流预报计算研究[J].水利水电技术,1997,28(9):16-19.
[2]姚鹏,王兴奎.异重流潜入规律研究[J].水利学报,1996(8):77-83.
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[4]董炳江,张小峰,陆俊卿,等.水库异重流潜入运动数值模拟及影响因素[J].武汉大学学报:工学版,2009,42(2):163-167.
[2]姚鹏,王兴奎.异重流潜入规律研究[J].水利学报,1996(8):77-83.
[3]李涛,张俊华,陈书奎,等.小浪底水库异重流潜入条件研究[J].中国农村水利水电,2011(10):91-92.
[4]董炳江,张小峰,陆俊卿,等.水库异重流潜入运动数值模拟及影响因素[J].武汉大学学报:工学版,2009,42(2):163-167.