近20年黄河下游宽滩区河槽糙率演变规律及影响因素分析  

Evolution of Channel Roughness and Influencing Factors in the Wide Floodplain of the Lower Yellow River in Recent 20 Years

作　　者：牛超杰 李东阳 赵连军[3] 韩沙沙 全李宇 李想[1] 胡彩虹[1] NIU Chaojie;LI Dongyang;ZHAO Lianjun;HAN Shasha;QUAN Liyu;LI Xiang;HU Caihong(School of Water Conservancy and Transportation,Zhengzhou University,Zhengzhou 450001,China;Henan Yellow River Survey,Planning,Design and Research Institute Co.,LTD.,Zhengzhou 450003,China;Key Laboratory of Yellow River Sediment of Ministry of Water Resources,Yellow River Conservancy Research Institute,Yellow River Conservancy Commission,Zhengzhou 450003,China;State Key Laboratory of Hydrology and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]郑州大学水利与交通学院,河南郑州450001 [2]河南黄河勘测规划设计研究院有限公司,河南郑州450003 [3]黄河水利委员会黄河水利科学研究院水利部黄河泥沙重点实验室,河南郑州450003 [4]清华大学,水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《应用基础与工程科学学报》2024年第4期984-999,共16页Journal of Basic Science and Engineering

基　　金：国家自然科学基金黄河联合基金项目(U2243219);国家自然科学基金项目(51979250,51739009)。

摘　　要：河槽糙率是影响黄河下游宽滩区洪水演进过程和河床冲淤变化的主要参数,2002年小浪底水库实施蓄水拦沙后,改变了河槽糙率的分布规律,糙率变化对下游河道防洪工程布局及生态环境保护规划等造成一系列影响.利用黄河下游宽滩区2002~2020年典型水文站实测断面数据和水文数据,根据曼宁公式推求糙率,分析典型大断面汛前、汛后河槽糙率随时空的演变规律及影响因素.结果表明:(1)同一断面汛后糙率略大于汛前糙率,花园口和孙口断面汛后糙率较汛前糙率增幅明显,增幅分别为14.64%和19.37%;(2)游荡段糙率随时空变化呈下降趋势,过渡段糙率随时空变化呈略微上升趋势;(3)河槽糙率随Froude数的增大而减小,糙率与含沙量之间没有表现出明显的相关关系;(4)以花园口和高村站为例,河槽糙率与流量和断面平均流速呈反比,与过流面积呈正比,游荡段糙率与宽深比呈反比,过渡段与宽深比呈正比;其中,糙率与平均流速之间拟合关系最好,R^(2)分别为0.62和0.78;(5)断面形态和水流条件是影响黄河下游宽滩区河槽糙率的关键因素.The key factor influencing flood evolution and the progression of riverbed erosion and silting in the wide floodplain of the Lower Yellow River(LYR)is channel roughness.The distribution law of channel roughness has changed since the implementation of water storage and sand control in Xiaolangdi Reservoir in 2002,and the change in roughness has had a number of effects on the design of flood control projects and ecological environment protection planning of the lower reaches.Manning’s formula was used to calculate the roughness based on cross-section data and hydrological data collected by typical hydrological stations in the wide floodplain of the LYR from 2002 to 2020.The evolution law and influencing factors of channel roughness of typical sections before and after floods were also examined.The findings indicate that:(1)The post-flood roughness was slightly higher than the pre-flood roughness in the same area.The post-flood roughness in the Huayuankou and Sunkou sections significantly increased compared to the pre-flood roughness,with an increase rate of 14.64%and 19.37%,respectively.(2)The time-to-space variation of roughness in the wandering section exhibits a decreasing trend,whereas the time-to-space variation of roughness in the transition section exhibits a slightly increasing trend.(3)The channel roughness decreases with an increase in Froude number,but there is no clear relationship between the roughness and sediment content.(4)Using Huayuankou and Gaocun stations as examples,the channel roughness is inversely proportional to the flow,the average sectional velocity,and the cross-section area of the flow.The channel roughness of the wandering section is inversely proportional to the ratio of width to depth,and the channel roughness of the transition section is proportional to the ratio of width to depth.Roughness and average velocity were determined to have the best-fitting connection,with R^(2)values of 0.62 and 0.78,respectively.(5)The main elements impacting channel roughness in the wide floodplain o

关 键 词：黄河下游 小浪底水库 宽滩区 糙率 弗劳德数 断面形态 水流条件 

分 类 号：TV131.2[水利工程—水力学及河流动力学]