三峡工程运用后荆江段崩岸过程及特点

发布时间：2018-04-12 23:15

本文选题：崩岸特点 + 崩岸机理　；参考：《水科学进展》2017年04期

【摘要】：为研究近期荆江段崩岸过程及特点,利用实测水下地形图及固定断面资料,分析了三峡工程运用前后该河段平面及断面的形态变化过程。平面形态对比结果表明:2002—2013年荆江段多年平均崩退速率约为15.0 m/a,崩岸总长达42.3 km,左岸占59.2%;下荆江岸线崩长约为上荆江的2.2倍,且石首、调关及荆江门等河湾凸岸一侧受低含沙水流长期冲刷不断崩退,其岸线崩长约占下荆江崩岸总长的35.5%。断面形态对比结果显示:2002—2015年荆江段约有21%断面存在明显的崩岸现象,且近74%的崩岸断面位于下荆江。故近期荆江段崩岸分布规律主要表现为左岸多于右岸,下荆江多于上荆江,且下荆江部分河湾凸岸崩退显著。定量分析了河岸土体组成与分布、来水来沙条件等因素对崩岸过程的影响,发现来水来沙条件的影响占主导地位。建立了上、下荆江典型断面平滩河宽与前期水沙条件之间的经验关系,除工程守护良好的断面外,相关系数均高于0.85,提出的经验公式可较好反映水沙条件变化对平滩河宽调整的影响。
[Abstract]:In order to study the process and characteristics of bank collapse in Jingjiang section in the near future, using the measured underwater topographic map and the data of fixed section, the morphological changes of the plane and section of the reach before and after the operation of the three Gorges Project are analyzed.The results of plane morphology comparison show that the average annual collapse rate of Jingjiang reach is about 15.0 m / a from 2002 to 2013, the total length of bank collapse is 42.3 km, the left bank is 59.2%, the length of the lower Jingjiang river bank is about 2.2 times that of the upper Jingjiang River, and the head of the stone is the same as that of the upper Jingjiang River.One side of the protruding bank of the estuary such as Jiaoguan and Jingjiangmen has been continuously washed and retreated by the low sediment flow for a long time, and its shoreline caving length accounts for about 35.5m of the total length of the bank of the lower Jingjiang River.The results show that 21% of the sections in the Jingjiang section from 2002 to 2015 have obvious bank collapse, and nearly 74% of the sections are located in the lower Jingjiang River.Therefore, in recent years, the distribution law of bank collapse in Jingjiang section mainly shows that the left bank is more than the right bank, the lower Jingjiang river is more than the upper Jingjiang river, and the lower Jingjiang part of the river bay has collapsed and retreated significantly.The influence of the composition and distribution of riverbank soil mass and the condition of incoming water and sediment on the process of bank collapse are quantitatively analyzed. It is found that the influence of the condition of incoming water and sediment is dominant.The empirical relationship between the width of Pingtan River in typical section of the upper and lower Jingjiang River and the conditions of water and sediment in the early stage is established, except for the well-guarded section of the project.The correlation coefficients are all higher than 0.85, and the empirical formula can better reflect the influence of the change of water and sediment conditions on the adjustment of the width of the Pingtan River.
【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;长江水利委员会水文局荆江水文水资源勘测局;
【基金】：国家重点研发计划资助项目(2016YFC0402303) 国家自然科学基金资助项目(51579186)~~
【分类号】：TV147

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