2022年“汛期反枯”对三峡库区泥沙冲淤的影响  

Impact of Severe Drought during Flood Season in 2022 on Sediment Erosion and Deposition in Three Gorges Reservoir

作　　者：邹红梅 陈芳 杨成刚 ZOU Hong-mei;CHEN Fang;YANG Cheng-gang(Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,China)

机构地区：[1]长江水利委员会水文局,武汉430010

出　　处：《长江科学院院报》2024年第7期190-195,202,共7页Journal of Changjiang River Scientific Research Institute

基　　金：长江水科学研究联合基金项目(U2040218);湖南省水利科技项目(XSKJ2022068-39)。

摘　　要：为深入分析2022年“汛期反枯”这一水文情势对三峡库区泥沙冲淤的影响,采用输沙量法评估三峡库区泥沙淤积总量变化,以断面法分析水库淤积的沿程分布情况。2022年汛期三峡水库入库径流量的大幅减少,致使库区的泥沙淤积规律较往年发生较大变化,主要表现为库区干流泥沙淤积量显著减少,仅淤积1097万t,为蓄水运用以来最低值。断面法计算结果表明库区河床冲刷0.157亿m^(3),且变动回水区和常年回水区均冲刷明显,出现“伪冲刷”现象。分析发现,汛期来沙大幅减少,无法补足淤积泥沙密实沉降造成的河床断面变化是造成库区出现“伪冲刷”的主要原因。建议加强库区淤积泥沙密实规律及影响机制研究,关注特殊水情下库区河床冲淤演变规律,以支撑三峡工程科学调度需要。This article delves into the impact of severe drought during the flood season in 2022 on sediment erosion and deposition in the Three Gorges Reservoir(TGR).Employing the sediment-transport balance method,we assessed the changes in total sediment deposition in TGR and utilized topographic change methods to analyze sediment distribution in the reservoir.These analyses reveal significant alterations in sediment deposition patterns compared to previous years due to inflow plunges in the flood season of 2022.The annual sediment deposition volume in the Three Gorges Reservoir,calculated at 10.97 million tons using the sediment balance method,has approached historically low levels since the impoundment.However,morphological cross-sectional calculation results indicate 15.7 million m^(3) of erosion in the reservoir’s riverbed,encompassing fluctuating and perennial backwater areas.The primary cause of this“pseudo-scouring”phenomenon is inadequate sediment input to offset riverbed settling.To address scientific scheduling needs for the Three Gorges Project,we recommend enhancing research on sediment compaction laws and influencing mechanisms in the reservoir area.Additionally,attention should be directed towards understanding the evolution of riverbed scouring and siltation under specific hydrological conditions.

关 键 词：泥沙淤积 汛期反枯 输沙量 径流 三峡库区 

分 类 号：TV145.1[水利工程—水力学及河流动力学]