| 引用本文: | 孙启航,夏军强,周美蓉,邓珊珊.三峡工程运用后城陵矶-武汉河段河床调整及崩岸特点.湖泊科学,2019,31(5):1447-1458. DOI:10.18307/2019.0526 |
| SUN Qihang,XIA Junqiang,ZHOU Meirong,DENG Shanshan.Characteristics of channel adjustments and bank erosion in the Chenghan reach after the Three Gorges Project operation. J. Lake Sci.2019,31(5):1447-1458. DOI:10.18307/2019.0526 |
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| 摘要: |
| 为研究近期城汉河段河床调整及崩岸特点，利用实测水沙及地形等资料，采用河段平均的方法，计算了城汉河段断面形态的调整过程，主要包括平滩河槽形态调整及其与前期水沙条件之间的关系.计算结果表明：城汉河段平滩河宽由2003年的1710 m增加至2016年的1732 m，增幅为1.28%，平滩水深由2003年的16.47 m增加至2016年的17.95 m，增幅为9.0%；白螺矶、界牌、簰洲及武汉等河段河床调整以纵向冲深为主，但陆溪口河段河床调整横向展宽与纵向冲深同步发展；2006-2016年城汉河段多年平均崩退速率为5.5 m/a，崩岸总长19.6 km，占岸线总长的8.3%，右岸占55.3%.簰洲河段岸线崩长占城汉河段岸线崩退总长的75.9%.此外还分析了河床边界与水沙条件等因素对重点河段（簰洲河段）崩岸过程的影响，来水来沙条件占主导地位，局部区域崩岸的发生依赖于河床边界条件；建立了典型断面平滩河宽与前期水沙条件之间的经验关系，较好地反映了水沙条件变化对崩岸过程的影响. |
| 关键词: 河床调整 平滩河槽形态 崩岸特点 城汉河段 三峡工程 |
| DOI：10.18307/2019.0526 |
| 分类号: |
| 基金项目:国家重点研发计划项目（2016YFC0402305）和国家自然科学基金项目（51725902，51579186）联合资助. |
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| Characteristics of channel adjustments and bank erosion in the Chenghan reach after the Three Gorges Project operation |
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SUN Qihang, XIA Junqiang, ZHOU Meirong, DENG Shanshan
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State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, P. R. China
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| Abstract: |
| The Chenghan reach is undergoing considerable channel degradation, and significant bank retreat processes have occurred at local sites due to the operation of the Three Gorges Project (TGP). The adjustment process of cross-sectional profiles in the Chenghan reach was investigated quantitatively by adopting the reach-average method and using the measured topographic and hydrological data after the TGP operation. It mainly covers the adjustment of bankfull channel dimensions and the relationship between these bankfull variables and the previous flow-sediment conditions. These results indicate that the bankfull channel width in the Chenghan reach increased from 1710 m in 2003 to 1732 m in 2016, with an increase of 1.28%. The bankfull channel depth increased from 16.47 m in 2003 to 17.95 m in 2016, with an increase of 9.0%. The channel adjustments in the subreaches of Bailuoji, Jiepai, Jiayu, Paizhou and Wuhan were mainly characterized by an increase in bankfull depth. The channel adjustments in Luxikou subreach behaved to have an increase in both depth and width. The average annual bank-erosion rate of the Chenghan reach from 2006 to 2016 was 5.5 m/a, and the cumulative bank-erosion length of 19.6 km accounted for 8.3% of the total length of the bankline, with 55.3% of the bank-erosion regions located at the right bank. The bank-erosion regions in the Paizhou subreach accounted for 75.9% of the total length of the retreated bankline in the Chenghan reach. Various factors influencing bank retreat in the key subreach of Paizhou have been presented, and the results indicate that the sediment hydrograph is a dominant control factor, and localized bank collapse depends on channel boundary conditions. Finally, empirical relationships were developed between the section-scale bankfull width at typical section with severe bank collapses and the average fluvial erosion intensity during flood seasons in previous years. The proposed empirical relation can consider the effect of the altered flow and sediment regime on the variation in bankfull width at a typical section. |
| Key words: Channel adjustments bankfull channel geometry bank retreat Chenghan reach Three Gorges Project |
