长江八卦洲河段河床形态对水沙变异的响应研究
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摘要
长江南京八卦洲河段是长江下游典型的分汊河段,汊道两岸特别是左汊分布了众多大型国有企业,其河势变化与经济发展密切相关。近年来长江流域水土保持、上游梯级枢纽修建等工程项目的实施,改变了南京河段来水来沙条件,使八卦洲汊道水沙过程发生变异,势必对河床演变造成影响。本文分析了南京八卦洲河段近期河床演变特性,结合水沙分析变化,分析预测该河段的演变趋势。分析结果表明:八卦洲汉道河床横断面形态参数与水沙因子拟合关系较好;随着右汊的河槽冲刷,河床将向窄深方向演变;左汊河槽淤积,河床向宽浅方向发展。
Nanjing Baguazhou reach of the Yangtze River is the lifeblood of the industrial development of Nanjing.On the banks of the channels,especially the left branches,there are quite a number of large state-owned enterprises.The change of river regime is closely related to economic development.Since1940 s,the left branch has changed from the main course to the secondary one,and the channel sedimentation and shrinkage has been a threat to the development of those enterprises.In recent years,The water and sediment fluxes coming from the Yangtze River have been changing,partly caused by the soil and water conservation and the constructions of dams,which will impact on the riverbed evolution of Baguazhou reach.Based on the measured data of runoff and sediment of Datong hydrological station,we forecast the tendency of riverbed evolution.The analysis of interannual variation and Baguazhou riverbed evolution shows:The river channel coefficient of the right branch is in a good coincidence with water and sediment parameters,while the right branch regime coefficient has no significant correlation with water and sediment parameters.The erosion of right branch channel is intensifying,and the cross section is changing forward to deep-narrow shape.The cross section of left branch is deposited to the wide-shallow shape.
Nanjing Baguazhou reach of the Yangtze River is the lifeblood of the industrial development of Nanjing.On the banks of the channels,especially the left branches,there are quite a number of large state-owned enterprises.The change of river regime is closely related to economic development.Since1940 s,the left branch has changed from the main course to the secondary one,and the channel sedimentation and shrinkage has been a threat to the development of those enterprises.In recent years,The water and sediment fluxes coming from the Yangtze River have been changing,partly caused by the soil and water conservation and the constructions of dams,which will impact on the riverbed evolution of Baguazhou reach.Based on the measured data of runoff and sediment of Datong hydrological station,we forecast the tendency of riverbed evolution.The analysis of interannual variation and Baguazhou riverbed evolution shows:The river channel coefficient of the right branch is in a good coincidence with water and sediment parameters,while the right branch regime coefficient has no significant correlation with water and sediment parameters.The erosion of right branch channel is intensifying,and the cross section is changing forward to deep-narrow shape.The cross section of left branch is deposited to the wide-shallow shape.
引文
[1]八卦洲整治动床模型试验报告[R].南京:河海大学,南京水利科学研究院.
[2]臧英平,仲琳,周玲霞,王鹤华.长江南京河段河势控制工程实践与思考[J].中国水利,2011(08):33—36.
[3]水利部长江水利委员会水文局.1998年长江洪水及水文监测预报.北京:中国水利水电出版社,2000.
[2]臧英平,仲琳,周玲霞,王鹤华.长江南京河段河势控制工程实践与思考[J].中国水利,2011(08):33—36.
[3]水利部长江水利委员会水文局.1998年长江洪水及水文监测预报.北京:中国水利水电出版社,2000.
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