三峡工程运用后上荆江枯水河槽调整及其对航道的影响

发布时间：2018-07-05 13:37

本文选题：枯水河槽 + 水沙条件　；参考：《工程科学与技术》2017年S2期

【摘要】：三峡工程运用后,上荆江河段河床冲刷较为剧烈,枯水(5 000 m3/s流量)河槽形态相应发生调整,对航运产生了较大影响。本文通过1维水动力学模型确定了各固定断面的枯水河槽形态参数。由于不同断面的河槽形态沿程存在显著差异,故采用基于对数转换的几何平均与断面间距加权平均相结合的河段平均方法,计算了2002—2015年上荆江河段尺度的枯水河槽形态参数。计算结果表明:受大范围护岸及护滩工程的影响,研究时段内上荆江枯水河槽宽度仅有小幅度增加,而相应的水深和面积增加约0.68 m及870 m2,增幅分别达12%及15%,航道条件总体上有所改善;枯水河槽宽深比呈持续减小趋势,由2002年的5.73减小至2015年的5.17,故近期上荆江枯水河槽形态趋于窄深;在火箭洲、沙市及公安弯道等局部河段,江心洲或凸岸边滩的剧烈冲刷导致河槽展宽,宽深比明显增加,引起局部水深不足、航槽不稳定等现象。此外通过分析河槽形态调整对前期水沙条件的滞后响应,建立河段尺度的枯水河槽形态参数与前6年平均汛期水流冲刷强度之间的经验关系。结果表明:受人类活动干扰,上荆江河段尺度的枯水河槽宽度与前期水沙条件的相关程度较低,故建立的枯水河槽宽度公式不能反映水沙条件变化对河宽调整的影响;上荆江河段尺度的枯水河槽水深、面积、宽深比与前6年平均汛期水流冲刷强度的相关程度分别为0.92、0.95及0.85,故这3个参数均可较好地对由于三峡工程运用引起的水沙条件改变做出快速响应。
[Abstract]:After the application of the three Gorges Project, the riverbed scour of the upper Jingjiang reach is more intense, and the channel shape of the dry water (5 000 m3 / s discharge) is adjusted accordingly, which has a great influence on the shipping. In this paper, 1 D hydrodynamic model is used to determine the morphological parameters of each fixed section of the low water channel. Because there are significant differences in the channel shape of different sections, the average method based on the geometric mean and the weighted average of the cross-section spacing based on the logarithmic transformation is adopted. The morphological parameters of the low water channel in the upper Jingjiang reach from 2002 to 2015 are calculated. The results show that the width of the low channel of the upper Jingjiang River increases only by a small margin during the study period due to the influence of a large area of bank protection and beach protection works. The corresponding water depth and area increased by 0.68 m and 870 m, respectively, by 12% and 15%, and the channel conditions improved, and the ratio of width to depth of the low water channel continued to decrease. From 5.73 in 2002 to 5.17 in 2015, the shape of the low water channel of the Upper Jingjiang River tends to narrow and deep in the near future, and the sharp scour of the Jiangxin Island or the shoreline along the convex bank leads to the widening of the channel and the obvious increase of the ratio of width to depth in the local river reach such as Rocket Island, Shashi City and Public Security Curves. Causes the partial water depth insufficiency, the navigation channel instability and so on phenomenon. In addition, by analyzing the lag response of channel shape adjustment to pre-stage water and sediment conditions, the empirical relationship between the morphological parameters of low water channel and the scour intensity of flow in average flood season of the previous six years is established. The results show that the correlation between the width of low water channel in upper Jingjiang reach and the condition of water and sediment is low, so the formula of the width of low water channel can not reflect the influence of the change of water and sediment condition on the adjustment of river width. The water depth and area of the low water channel in the upper Jingjiang reach, The correlation between the ratio of width to depth and the average flood season scour intensity in the previous six years is 0.92 ~ 0.95 and 0.85, respectively. Therefore, these three parameters can make a rapid response to the change of water and sediment conditions caused by the application of the three Gorges Project.
【作者单位】：武汉大学水资源与水电工程科学国家重点实验室;
【基金】：国家自然科学基金资助项目(51579186;51339001) 国家重点研发计划课题资助项目(2016YFC0402303/05)
【分类号】：TV147.5

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