三峡水库运行后荆江段河湾平面形态演变特征

发布时间：2018-04-22 00:17

  本文选题：河湾 + 平面形态演变　； 参考：《水力发电学报》2017年06期

【摘要】：目前对三峡水库运行后下游水文泥沙特性变化、河道冲刷与崩岸等问题已有认识,但对河湾平面形态演变还少见论述。本项研究基于研究区枯水期遥感影像,分析了三峡水库运行10余年来荆江段枯水河湾平面形态的演变特征。结果表明,枯水河湾的中心线长度、凸岸长度、凹岸长度、弯曲率和中心轴长度存在显著变异,以下荆江段的变异程度更大,凸、凹岸及上、下荆江段在演变过程上存在非同步性。上荆江段凹岸先于凸岸发生显著变异,且平面形态演变以凹岸冲刷延伸占主导作用,下荆江段凸岸先于凹岸显著变异,并以凸岸冲刷收缩占主导。大部分河湾尤其在下荆江,表现为面积、平均宽度明显增加,而中心线长度、弯曲率与中心轴长度减小,河湾发展具有河道冲刷展宽但弯曲退缩的特征。还讨论了平面形态演变与凸、凹岸冲淤变化的关系。
[Abstract]:At present, the changes of hydrologic and sediment characteristics, channel erosion and bank collapse in the lower reaches of the three Gorges Reservoir have been recognized, but the evolution of the river bay plane is rarely discussed. Based on the remote sensing images of the dry season in the study area, the evolution characteristics of the flat shape of the low water estuary in Jingjiang reach during the past 10 years of operation of the three Gorges Reservoir are analyzed. The results show that there are significant variations in the centerline length, convex bank length, concave bank length, bending rate and central axis length of the low water estuary, and the variation degree of the Jingjiang section below is greater, convex, concave and upper. There is nonsynchronism in the evolution of the lower Jingjiang section. The concave bank of the upper Jingjiang section had significant variation before the convex bank, and the plane morphology evolution was dominated by the erosion extension of the concave bank, the significant variation of the convex bank in the lower Jingjiang section was earlier than the concave bank, and the dominant factor was the erosion and contraction of the convex bank. Most of the estuaries, especially in the lower Jingjiang River, show a significant increase in area and average width, while the centerline length, the bending rate and the central axis length decrease. The river bay development has the characteristics of river channel scouring and bending and shrinking. The relationship between the evolution of plane morphology and the erosion and deposition of convex and concave banks is also discussed.
【作者单位】： 湖北民族学院生物科学与技术学院;湖北民族学院生物资源保护与利用湖北省重点实验室;
【基金】：国家自然科学基金(31460132) 湖北民族学院博士启动基金(D2014196)
【分类号】：TV147
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本文编号：1784752