小浪底水库降水排沙对其下游河床演变的影响  

Impacts of sediment flushing of Xiaolangdi Reservoir on fluvial processes in the Lower Yellow River

作　　者：申冠卿[1] 张原锋[1] 王平[1] 张广明 SHEN Guanqing;ZHANG Yuanfeng;WANG Ping;ZHANG Guangming(Yellow River Institute of Hydraulic Research,Zhengzhou 450003,China)

机构地区：[1]黄河水利科学研究院,河南 郑州450003

出　　处：《水科学进展》2024年第6期927-937,共11页Advances in Water Science

基　　金：国家自然科学基金资助项目(U2243218);河南省重大科技专项资助项目(231100320100)。

摘　　要：为充分认识水库排沙对其下游河床演变及防洪的影响,基于2018—2020年黄河水沙观测资料,研究了小浪底水库排沙期黄河下游河道泥沙输移规律、排洪“瓶颈”河段与宽河段泥沙空间调整及洪水前后水沙关系变化。结果表明:2018—2020年6场洪水共排沙10.911亿t,下游河道淤积比为58.0%~84.2%,明显大于1965—1999年与之来沙系数相近的洪水,泥沙淤积以粗沙占比最大,粗沙、中沙及细沙占比分别为44.4%、29.0%和26.6%;淤积主要集中在花园口以上河段,占比为79.1%,花园口—高村、高村—艾山段占比分别为15.9%和3.5%,花园口以上富余的河槽容积对暂滞泥沙发挥了有效作用,洪水期淤积物一般在排沙后当年或之后1~2 a内可被冲走,对河道排洪基本无影响;洪水期悬沙与床沙相互交换,悬沙沿程变细,洪水过后花园口站床沙细化较明显。水库洪水期相机排沙改善了洪水后水沙关系,提高了水资源利用效率。研究成果丰富了多沙河流修建水库对下游河床演变影响的认识,为河道防洪及水库水沙调控提供了技术支撑。To comprehensively realize the effects of reservoir sediment flushing on fluvial processes and downstream flood control,this study examines flood routing and sediment transport,as well as changes in erosion and sediment patterns within the bottle-neck reach of flood conveyance and the widened reach in the Lower Yellow River(LYR).This analysis employs measured data from the reservoir and river course collected from 2018 to 2020 and allows for assessing changes in the water—sediment relationship before and after flood events.The obtained results reveal that the total sediment load of 6 floods discharged by Xiaolangdi Reservoir(XLD)amounted to 1.09 billion tons.The ratios of the deposition to incoming sediment load in the LYR ranged from 58.0%to 84.2%,significantly higher than those observed in flood events with similar incoming sediment ratios from 1965 to 1999.Coarse sediments accounted for the largest share with 44.4%,followed by medium sediments at 29.0%,and fine sediments at 26.6%.Most of the deposition,79.1%,occurred upstream of Huayuankou(HYK),with HYK—Gaocun and Gaocun—Aisan accounting for 15.9%and 3.5%of the deposition respectively.The channel storage upstream of HYK played a role in temporarily detaining the sediment.The deposition that occurs during flood periods can be washed away within 1 to 2 years after the flood,without adversely affecting the flood-carrying capacity of the channel.The exchange of suspended sediment with bed materials led to the refining of suspended particles along the river course.After the flood,significant bed material refinement was observed at the HYK station..Sediment flushing of the reservoir during flood period improves the water—sediment relationship post-flood and increases the efficiency of water resource utilization.The findings of this study advance the scientific understanding of the impacts of reservoirs on sediment-laden rivers and their downstream fluvial processes also provides technical support results for channel flood control and water-sediment regulatio

关 键 词：河床演变 水库排沙 泥沙输移 水沙关系 黄河下游 

分 类 号：TV121[水利工程—水文学及水资源] P339[天文地球—水文科学]