鄱阳湖入江水道输沙能力与出湖沙量关系及冲淤调整规律  

Relationship between sediment transport capacity of the Poyang Lake channel and sediment out of the lake and adjustment

作　　者：方春明[1] 关见朝[1] 史红玲[1] FANG Chunming;GUAN Jianzhao;SHI Hongling(China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国水利水电科学研究院泥沙研究所,北京100048

出　　处：《水利学报》2023年第8期997-1004,共8页Journal of Hydraulic Engineering

基　　金：三峡后续工程项目(12630100100020J005)。

摘　　要：鄱阳湖是长江流域生态系统的重要组成部分,近年来鄱阳湖枯水水位下降、枯水时间提前呈常态化和趋势性变化引起了广泛研究。鄱阳湖入江水道作为江湖联系的纽带,在江湖关系演变中起着重要作用。特别是2001年以来,入江水道演变和出湖沙量出现了显著和复杂的变化过程,其原因存在明显争议。本文采用水文泥沙观测资料结合机理研究,分析阐明了鄱阳湖入、出湖水沙变化与入江水道挟沙能力变化关系及冲淤调整规律。研究结果表明:入江水道代表断面月流速与湖口月出湖含沙量成正比,鄱阳湖出湖沙量与入江水道输沙能力直接相关;入湖泥沙对入江水道演变的影响是缓慢的,入湖沙量集中的4—6月,1985年前后各月出湖沙量减少量和减小比率都小于入湖沙量减少量和减小比率,都大于输沙能力减小比率;1998—2010年与1955—1998年比,月出湖含沙量变化比率与入江水道月挟沙能力变化比率具有较好关系;从出湖含沙量与代表断面流速关系看,1999—2010年出湖含沙量在不考虑断面变化情况下总体低于1955—1998年相关线,考虑断面扩大后则高于1955—1998年相关系,说明1999—2010年出湖含沙量增大和入湖水道断面扩大是冲刷和采砂共同影响的结果;入江水道下段代表断面2011—2020年同流速下顺出湖含沙量与1955—1998年关系线基本一致,而上段代表断面则明显低于1955—1998年关系线,说明入江水道下段已趋于稳定,上段仍可能会有一定的冲刷调整,引起湖区枯水位继续有所下降。本文研究结果对明晰鄱阳湖入江水道冲淤变化、长江与鄱阳湖相互影响复杂关系和指导鄱阳湖保护与治理具有重要意义。Poyang Lake is an important part of the ecosystem of the Yangtze River Basin.In recent years,the low water level of Poyang Lake and its low water time have shown regular and trend changes,which have caused extensive research.As a link between the Yangtze River and the lake,the Poyang Lake channel plays an important role in the evolution of the river-lake relationship.Especially since 2001,there has been a distinct and complex process of changes and the reasons for this are obviously controversial.Based on hydrological and sediment observations and mechanism studies,the relationship between the sediment changes flow into and out of Poyang Lake and the sediment carrying capacity of the channel was analyzed.Research indicates:The monthly flow velocity of the representative section of the channel is proportional to the monthly sediment concentration out of the lake.The sediment volume out of the lake is directly related to the sediment transport capacity of the channel.The effect of the inflow sediment on the evolution of the channel was slow.From April to June,when the inflow sediment was concentrated,the reduction amount and ratio of the outflow sediment were smaller than the reduction amount and ratio of the inflow sediment,and were larger than the reduction ratio of the sediment transport capacity in each month around 1985.Compared with 1955-1998,the change ratio of monthly sediment concentration out of the lake had a good relationship with the change ratio of the monthly sediment-carrying capacity of the channel.From the relationship between the sediment concentration out of the lake and the velocity of the representative section,the sediment concentration from 1999 to 2010 was generally lower than the correlation line from 1955 to 1998 without considering the change of the section,and was higher than the correlation line from 1955 to 1998 after considering the expansion of the section.The results indicate that the increase of sediment concentration and the expansion of channel section from 1999 to 2010 are the

关 键 词：鄱阳湖入江水道 入湖沙量 输沙能力 出湖沙量 冲淤调整 

分 类 号：TV142[水利工程—水力学及河流动力学]