| 周炜兴,孙昭华,杨中华,李芷晴,安姗姗.三峡建库前后荆江沙质河段流量-输沙率关系及其变化机理[J].水利学报,2025,56(8):1049-1060,1071 |
| 三峡建库前后荆江沙质河段流量-输沙率关系及其变化机理 |
| Sediment-transport rating curves and their variation mechanisms in sandy reach of the Jingjiang River before and after construction of the Three Gorges Reservoir |
| 投稿时间：2024-12-09 修订日期：2025-08-01 |
| DOI：10.13243/j.cnki.slxb.20240802 |
| 中文关键词: 流量-输沙率关系 泥沙输移状态 滩槽冲淤 荆江河段 三峡水库 |
| 英文关键词: sediment-transport rating curve sediment transport mode channel-floodplain deformation Jingjiang River the Three Gorges Reservoir |
| 基金项目:国家自然科学基金项目（52479074）；水利部三峡后续研究项目（12630100100020J005） |
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| 中文摘要: |
| 三峡建库前后荆江沙质河段内流量-输沙率关系明显变化，会对滩槽冲淤分布产生一定影响。本文收集了三峡建库前后沙市-城陵矶河段内水文、泥沙和河道地形资料，系统研究了建库前后流量-输沙率关系，从漫滩前后断面形态、水动力条件和泥沙输移状态等角度揭示其变化机理及对河道冲淤的影响。主要结论有：三峡建库前流量-输沙率关系曲线在平滩流量以上呈向下偏转，是由于水流漫滩后主槽区输移泥沙以冲泻质为主导，这部分泥沙进入滩地后转化为床沙质而参与造床。在三峡建库后，输沙率曲线在平滩流量以上的偏转特性消失，反而在枯水流量下出现临界特征。这是由于建库后总体滩槽形态、水动力格局虽未发生显著变化，但泥沙粒径粗化导致泥沙输移状态发生由冲泻质向床沙质（漫滩以上流量级）、悬移质向推移质（基流枯水期）的质变。在建库后流量-输沙率关系影响下，主槽发生明显冲刷，滩地淤积速度将会减缓。本文可加强对三峡水库下游沙质河段内平衡/非平衡状态下水沙输移机制理解，并为河道长期冲淤趋势判断提供参考。 |
| 英文摘要: |
| The sediment-transport rating curves（STCs）in the sandy reach of the Jingjiang River have varied significantly due to the construction of the Three Gorges Reservoir （TGR），impacting channel-floodplain deformation dynamics. This paper examined the mechanisms underlying the variations in STCs influenced by TGR construction， utilizing hydrological，sediment，and river topography data，and analyzed their implications for channel-floodplain deformation. Main conclusions indicate that prior to TGR construction，the STC exhibited a downward deflection above bankfull discharge. This phenomenon was attributed to predominance of wash load transported in the main channel，which subsequently entered the floodplain as overbank flow and transformed into bed load. Following TGR construction，the deflection of STC above bankfull discharge disappeared，revealing a critical characteristic under low flow condition instead. Although overall channel-floodplain morphology and hydrodynamic regimes have not changed significantly since TGR construction，the coarsening of sediment particle size has led to qualitative shifts in sediment transport modes：from wash load to bed load above bankfull discharge，and from suspended load to bed load during dry periods. Influenced by altered sediment transport regimes，the main channel experiences significant scour，while sedimentation rates on the floodplain are markedly reduced. This understanding enhances our comprehension of water-sediment transport mechanisms under both equilibrium and non-equilibrium conditions in a dammed sandy river，as well as long-term evolutionary trends of river channel. |
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