【摘要】 20世纪80年代以来,珠江三角洲水文情势发生了显著的变化。为研究东江下游及三角洲河网河道特性,基于河床演变、主要水文站H-Q曲线、比降与糙率的比值系数等分析结果,建立一维河网数学模型,推求基于1997年实测地形的河道综合糙率系数。结果表明:河床下切致使主要控制水文站博罗站H-Q曲线呈不断下降,利用历史K值推求的博罗站H-Q曲线高水部分相对合理。东江三角洲河道糙率在三角洲顶部较大,三角洲下部河道糙率较小,河段糙率在0.02～0.03之间,糙率取值与1989年水面线基本一致。本次水面线选取的石龙汊口附近糙率较大,这与该处河道床面坡降较大有关。更多还原

【Abstract】 Since the 80 s of last century,the hydrological situation of the Pearl River Delta has changed significantly. In order to analyze the channel characteristics of the Dongjiang River and Delta River network,based on the analysis of river bed evolution,H-Q curve of main hydrological stations and ratio coefficient of specific drop to roughness,a one-dimensional numerical model of river network is established in this paper,and the comprehensive roughness coefficient of river network based on the measured topography in 1997 is deduced as well. It shows that as the river topography deepens in Dongjiang River and delta,the water level of the Boluo hydrological station drops under the same discharge. Using the 1966 K value to extend the K value near curve of 2000,we can get a relatively reasonable H-Q curve of large flow volume in Boluo under the 1997 topography. The river roughness in the East River Delta is larger than the top of the Delta,the roughness of the downstream of the delta is smaller,the roughness of the river is between 0.02 ～ 0.03,and the roughness is basically the same as that of the water surface line in1989. The surface roughness of the Shilong river mouth is larger than that of other river because of its large slop.更多还原