| 摘要: |
| 根据长江口南港河段历史地形资料和1997—2011年4次固定断面水深测量资料，分析了南港河槽整体及分区域容积变化过程，重点分析了中潮位、5 m以深河槽容积变化特征。分析研究表明：瑞丰沙中部串沟和人类无序采砂导致2001—2004年河槽容积季节性变化剧烈，长兴水道深槽和南港主槽深槽均淤积。2001—2007年南港河槽基本处于洪淤枯冲状态。2001年前及2008年后季节性变化均为洪冲枯淤，2008年后季节性变化减弱；南港河槽容积长期处于增大趋势，2001年开始，由于瑞丰沙中部串沟，长兴水道由涨潮占优转变为落潮占优，不断淤积，一直持续到2008年。南港主槽上段北淤南冲，中下段南淤，主泓北偏，由于瑞丰沙的冲刷，河槽总容积仍呈增大趋势。2008年后河槽进入发展期；南港河槽上段深淤浅冲，幅度较小，中段串沟导致水流挟带大量泥沙在下游瑞丰沙嘴淤积；三峡工程运行后瑞丰沙嘴冲刷较为剧烈。 |
| 关键词: 长江口 南港 河槽容积 冲淤变化 |
| DOI： |
| 分类号:TV148 |
| 基金项目:国家自然科学基金青年科学基金资助项目（51009095） |
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| Characteristics analysis of changes in scouring and silting volumes of south channel of Yangtze estuary |
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ZHU Yuan1, LUO Xiao-feng2
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1.Shanghai Water Engineering Design and Research Institute Co., Ltd., Shanghai;2.State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing
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| Abstract: |
| Based on the historical bathymetry data of the south channel of the Yangtze River estuary, and the water depth of the fixed cross-sections four times every year from 1997 to 2011, the process of changes in the volumes of the overall and sub-regional south channel is analyzed in this study. The paper focuses on the characteristics analysis of the tide and changes in the volumes along 5 m deep river channel. The analysis results show that: (1) from 2001 to 2004, the Ruifeng shoal ditch and the human disorder sand-digging on the sand ridge of the south channel brought about a remarkable change in the river channel’s volumes while the deep channel of both Changxing waterway and the main channel of the south channel were in a deposition period; from 2001 to 2007, the south channel the alternate deposition and erosion in the flood season and non-flood season . After 2008, the south channel presented the alternate erosion and deposition in the flood season and non-flood season. This situation also occurred before 2001. However, this seasonal variation weakened after 2008. (2) There is a long-term increase in the riverbed volumes of the south channel. The deposition continued to exist in 2008 as the ebb tide was dominant, instead of the flood tide dominant, in the Ruifeng shoal ditch and Changxing waterway, starting from 2001. There was deposition in the north and erosion in the south at the upper section of the main channel of the south channel, and the south section of the middle-lower reach was scoured, with its thalweg moving to the north. But the erosion of Ruifeng shoal resulted in a trend of increasing in the south channel volumes. Since 2008, the river channel has been in a period of development. (3) There is a slight deposition along the deep channel and an erosion along the shoal, and there is a great amount of sediment, carried by flow from the ditches on the middle section, accumulating along the lower Ruifeng sand spit. The fact is found that the Ruifeng sand spit has been eroded severely since the operation of the Three Gorges project. |
| Key words: Yangtze River estuary the south channel river channel volume erosion and deposition |
