| 摘要: |
| 三峡水库蓄水后，窑监河段上游的来水来沙条件发生改变，使河床发生相应调整。三峡工程不仅引起该河段年际间水沙特征变化，含沙量显著减小，年内水沙过程也发生变化，表现为蓄水期流量减少，退水过程加快。根据现有实测地形数据，对三峡水库蓄水前后2002和2007年年内监利河段河床冲淤分布、横断面变化与航道条件进行了比较，并采用资料分析、数学模型等方法对航道条件变化的原因进行了分析。研究表明：三峡水库蓄水后，监利河段年内仍遵循蓄水前“涨淤落冲”的规律；汛期淤积强度较蓄水前减弱，汛后冲刷动力也有所减小，水沙不利年份时航道条件仍呈恶化态势。 |
| 关键词: 年内演变规律 退水冲刷 三峡水库 窑监河段 |
| DOI： |
| 分类号:TV147 |
| 基金项目:国家“973计划”资助项目（2012CB417002）；“十二五”国家科技支撑计划资助项目（2012BAB04B03）；中央级公益性科研院所基本科研业务（Y211001） |
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| Annual analysis of Yaojian reach riverbed evolution before and after impoundment of the Three Gorges reservoir |
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REN Fang-fang1,2, ZUO Li-qin2, LU Yong-jun2
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1.State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering, Hohai University;2.Nanjing Hydraulic Research Institute
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| Abstract: |
| Due to the impoundment of the Three Gorges project (TGP), runoff process and sediment conditions in the Yaojian reach of the middle Yangtze River, and the riverbed evolution is also changed correspondingly. Owing to operation adjustment of the TGP, the water and sediment inter-annual characteristics are changed, sediment concentration decreases significantly, and the characteristics of discharge and sediment process within a year are changed. After the impoundment of the TGP, the discharge during storage water period was decreased,and the recession duration after flood was shortened. Based on the measured data in 2002 and 2007 before and after the impoundment of the TGP, the difference between 2002 and 2007 has been analyzed in aspects of the riverbed erosion and deposition, the cross-section changes and the navigation channel conditions. In order to study the influences of the TGP on the navigation channel in the Yaojian reach, water and sediment data, the measured terrain data were collected, water-sediment flux analyzing has been done, and a 2D mathematical model was established and used to calculate the deposition and erosion of the Yaojian reach. The analysis results show that the evolution patterns within a year is characterized by “siltation during flood season and erosion during dry season”. As the sediment concentration decreases during the flood season, siltation in the Yaojian reach decreases compared with that before the impoundment of the TGP. The navigation channel is still under the unfavorable conditions. This is mainly caused by the impoundment of the TGP after the flood season, which changes the flow falling process, decreases the flow discharge, and thus decreases the erosion dynamics. |
| Key words: evolution law within a year erosion during flow falling the Three Gorges reservoir Yaojian reach |
