近期黄河下游游荡段河床下切特点及影响因素  

Characteristics and Influencing Factors of River Bed Incision in the Braided Reach of the Lower Yellow River in Recent Years

作　　者：周哲瀚 李洁 朱大伟[3] 黄祥[1] 朱呈浩 ZHOU Zhe-han;LI Jie;ZHU Da-wei;HUANG Xiang;ZHU Cheng-hao(College of Hydraulic Science and Engineering,Yangzhou University,Yangzhou 225009,Jiangsu Province,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,Hubei Province,China;Jiangsu Surveying and Design Institute of Water Resources Co.,LTD,Yangzhou 225009,Jiangsu Province,China;Yellow River Engineering Consulting Co.,LTD,Zhengzhou 450003,Henan Province,China)

机构地区：[1]扬州大学水利科学与工程学院,江苏扬州225009 [2]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [3]江苏省水利勘测设计研究院有限公司,江苏扬州225009 [4]黄河勘测规划设计研究院有限公司,河南郑州450003

出　　处：《中国农村水利水电》2025年第1期47-53,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(52109102);水资源工程与调度全国重点实验室开放基金项目(2020HLG01);扬州大学青蓝工程项目。

摘　　要：小浪底水库运行后,黄河下游游荡段冲刷剧烈,研究其河床下切特点及影响因素对游荡段河道整治具有重要意义。利用1999-2020年黄河下游游荡段28个淤积断面汛后实测地形数据,计算了游荡段各断面及河段河床累计下切深度及平滩水深,利用水文资料得到了各水文站逐年水位-流量关系曲线,并计算了一定流量下水位的逐年变化。结果表明:(1)1999-2020年黄河下游累计冲刷量达20.5亿m^(3),其中游荡段冲刷量最大,约为14.7亿m^(3)。(2)黄河下游游荡段在2000-2007年期间河床下切最为剧烈,多年平均河床下切深度达0.24 m/a,2008-2020年游荡段河床下切程度有所减弱,多年平均河床下切深度减小至0.05 m/a。(3)各站水位-流量关系发生了较大变化,游荡段各站给定流量下水位下降明显,沿程水文站水位下降存在一定的时间滞后,滞后时间约3~4 a。各站在500 m^(3)/s下的水位下降幅度均大于3 000 m^(3)/s水位下降幅度,其中高村站的下降幅度最大。(4)游荡段平滩水深由1999年的1.6 m逐步增大到2018年的4.0 m,之后又降低至2020年的3.8 m。(5)从来水来沙条件和河床边界条件两方面探讨了影响游荡段河床累计下切深度的因素,发现前期6年平均来沙系数是影响累计平均河床下切深度的关键水沙因子,定量揭示了游荡段持续的河床粗化对河床下切起抑制作用。Dramatical channel erosion has occurred in the braided reach of the Lower Yellow River(LYR)since the Xiaolangdi Reservoir operation.Study on characteristics and influencing factors of river bed incision has great significance for the river embankment and flood control in the braided reach of the LYR.The accumulated downcutting depths of river bed and channel bankfull depths were calculated based on the observed post-flood profiles at 28 cross-sections in the braided reach from 1999 to 2020.The annual water level-discharge curves of each hydrological station were obtained based on the hydrological data,and the annual change of water level at certain discharges was calculated.The results show that:①The cumulative scour volume of the LYR was 2.05 billion m3,and the braided reach experiencing the most channel erosion with a cumulative scour volume of approximately 1.47 billion m3 from 1999 to 2020.②The braided reach of the LYR experienced the most severe river bed downcutting between 2000 and 2007,with an average annual downcutting depth of 0.24 m/a.From 2008 to 2020,the degree of river bed downcutting in the braided reach decreased,with the average annual downcutting depth reducing to 0.05 m/a.③There have been significant changes in the water level-discharge relationships at three hydrological stations,with a noticeable decrease in water levels at given discharges at the three hydrological stations.There is a certain time lag in the decline of water levels at hydrological stations along the braided reach,with a lag time of approximately three to four years.The magnitude of water level decline at each hydrological station under a discharge of 500 m^(3)/s is greater than that under a discharge of 3000 m^(3)/s,with the largest decline observed at Gaocun station.④The bankfull depth in the braided reach increased from 1.6 m to 4.0 m from 1999 to 2018,and then decreased to 3.8 m in 2020.⑤Influencing factors of river bed cumulative incision were investigated quantitively,including incoming flow and sediment regim

关 键 词：河床下切 来沙系数 小浪底水库 游荡段 黄河下游 

分 类 号：TV147[水利工程—水力学及河流动力学]