黄河下游河道横断面变化特点及对弯道的影响
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摘要
黄河下游河道横断面变化直接关系河道的排洪输沙能力,横断面形态变化对弯道曲率的影响关系着河道的河势变化,一直是黄河下游河床演变研究的重点。从1986—1999年淤积缩窄时期和2000—2013年冲刷展宽时期入手,采用实测大断面数据,对黄河下游各河段横断面冲淤情况进行分析,给出了弯道曲率与横断面形态特征的关系式,分析了黄河下游横断面形态变化对弯道曲率的影响。结果表明:黄河下游河道各河段在冲刷时期,主槽宽逐渐变大,在理想条件下河道宽浅,弯道流中流速横向分布不均,容易造成塌岸冲刷,河道将会越来越弯曲。
The change of river section in the Lower Yellow River is directly related to the discharge capacity of river,and the change of cross section shape on the curvature of channel is related to the change of river regime.Based on the cross section data during deposition period from 1986 to 1999 and erosion period from 2000 to 2013,the deposition and erosion of river cross-sections in the Lower Yellow River was analyzed respectively.Based on theoretical analysis,the relation of the cross-sectional shape and the bend curvature was given.Finally,the effect of the change of cross-section shape on the curvature in the Lower Yellow River was analyzed.The results show that,during the erosion period,the main channel width gradually increases(under ideal conditions),the channel will become wider and shallower,the lateral distribution of the flow velocity in the curved channel is not uniform,which is easy to cause the erosion of the bank,and the channel will be more curved.
The change of river section in the Lower Yellow River is directly related to the discharge capacity of river,and the change of cross section shape on the curvature of channel is related to the change of river regime.Based on the cross section data during deposition period from 1986 to 1999 and erosion period from 2000 to 2013,the deposition and erosion of river cross-sections in the Lower Yellow River was analyzed respectively.Based on theoretical analysis,the relation of the cross-sectional shape and the bend curvature was given.Finally,the effect of the change of cross-section shape on the curvature in the Lower Yellow River was analyzed.The results show that,during the erosion period,the main channel width gradually increases(under ideal conditions),the channel will become wider and shallower,the lateral distribution of the flow velocity in the curved channel is not uniform,which is easy to cause the erosion of the bank,and the channel will be more curved.
引文
[1]陈建国.黄河下游河道萎缩机理与基本输水输沙通道规模研究[D].武汉:武汉大学,2013:1-10.
[2]夏军强,吴保生,王艳平.近期黄河下游河床调整过程及特点[J].水科学进展,2008,19(3):301-308.
[3]胡春宏,张治昊.黄河下游复式河道滩槽分流特征研究[J].水利学报,2013,44(1):1-9.
[4]吴保生,李凌云.黄河下游河道横断面的若干特点[J].人民黄河,2008,30(2):15-16.
[5]申冠卿,张原峰,尚红霞,等.不同时期黄河下游河道泥沙沉积与纵横断面调整[J].泥沙研究,2005(3):30-34.
[6]CHANG H H.Fluvial Processes in River Engineering[M].Florida:Krieger Publishing Company,1992:261-297.
[7]ODGAARD A J.Transverse Bed Slope in Alluvial Channel Bends[J].Journal of the Hydraulics Division,1981,107:1677-1694.
[2]夏军强,吴保生,王艳平.近期黄河下游河床调整过程及特点[J].水科学进展,2008,19(3):301-308.
[3]胡春宏,张治昊.黄河下游复式河道滩槽分流特征研究[J].水利学报,2013,44(1):1-9.
[4]吴保生,李凌云.黄河下游河道横断面的若干特点[J].人民黄河,2008,30(2):15-16.
[5]申冠卿,张原峰,尚红霞,等.不同时期黄河下游河道泥沙沉积与纵横断面调整[J].泥沙研究,2005(3):30-34.
[6]CHANG H H.Fluvial Processes in River Engineering[M].Florida:Krieger Publishing Company,1992:261-297.
[7]ODGAARD A J.Transverse Bed Slope in Alluvial Channel Bends[J].Journal of the Hydraulics Division,1981,107:1677-1694.