黄河河口段河道糙率计算方法  

A Formula for Channel Roughness for the Yellow River Estuary

作　　者：王万战[1,2] 张世安 Jeffrey A Nittrouer WANG Wanzhan;ZHANG Shian;Jeffrey A Nittrouer(Yellow River Institute of Hydraulic Research,Zhengzhou 450003,China;School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;Department of Earth Science,Rice University,Houston TX77005-1892,USA)

机构地区：[1]黄河水利科学研究院,河南郑州450003 [2]华北水利水电大学水利学院,河南郑州450045 [3]莱斯大学地球科学学院

出　　处：《人民黄河》2018年第12期4-8,共5页Yellow River

基　　金：国家重点研发计划项目(2017YFC0405501);黄河水利科学研究院基本科研业务费专项(HKY-JBYW-2017-18;HKY-JBYW-2016-27);水利部黄河泥沙重点实验室开放课题基金资助项目(2015002)

摘　　要：为了克服固定糙率法低估小流量水位的缺点,基于黄河口利津站糙率—流速实测资料,回归分析得出了糙率(曼宁系数)计算公式及河道参数a的计算式。通过一维数学模型模拟发现,在枯水期、非枯水期参数a值分别采用枯水期参数a的平均值、全年平均值时,得出的动态糙率可较好地模拟小流量和大流量水位。参数a与主槽内嫩滩附近地形有较密切的对应关系,可采用在嫩滩上、下附近取特征水位,进而计算其对应的水力半径、比降的方法来估算非枯水期、枯水期的参数a值。利津—口门床面形态在较大流量时多为动平整,对应的糙率较小,在糙率变化区间的下界0.01附近变化;流量较小时床面形态多为沙垄,对应的糙率较大,糙率在接近其上界0.035附近变化。在黄河口河道,影响糙率的主要因素是流速和河道水力半径,床沙粒径对糙率影响较小。In response to the underestimation of the water level for low flow rates for a constant Manning coefficient, the current authors usedthe data of velocity （v） and Manning coefficient （n） measured in the Yellow River estuarine channel to establish a new formula for channelroughness for the estuary, which takes the form of n = av^-1, a = R^2/ 3 J^1/ 2taken as a constant parameter over a certain period. The parameter（a） is found to make the calculated water level processes in the low flow season and the non-low flow season match the measured ones wellwhen it is taken as the average of the daily values over the low flow season and over one year respectively. The parameter （a） could be easilyestimated by using the characteristic water levels near the low flow floodplain within the channel. Bed form in the about 108 km channel fromLijin to the river mouth tends to be plane bed for larger flow rates, resulting in Manning coefficient varying near the lower bound of 0.01 whileit tends to be dunes for smaller flow rates, resulting in it changing near the upper bound of 0.035. The significant factors for Manning coffi-cient are velocity and hydraulic radius with the sizes of bed materials insignificant in the Yellow River estuarine channel.

关 键 词：小流量 水位 水力半径 流速 一维水动力模型 主槽糙率 黄河口 

分 类 号：TV856[水利工程—水利水电工程] TV882.1