三峡库区黄花城河段环流结构与涡尺度特征初探

Primary study on circulation structures and vortex-scale characteristics of Huanghuacheng reach in the Three Gorges Reservoir area

弯道水流结构在天然河流形态演变过程中起着重要作用,为进一步深化对弯道环流结构与紊动特性的认识,以三峡库区黄花城河段具有的连续弯道为研究对象,采用声学多普勒剖面流速仪(ADCP)开展原型三维瞬时速度测量,初步分析弯道环流结构与湍流结构尺度分布特性。研究结果表明:三峡库区黄花城河段存在河道层面宏观尺度的弯道环流结构;受局部壅水以及河床地形影响,在测量垂线上表现为全水深环流结构或双环流结构特征;超大尺度湍流结构仍然存在于库区连续弯道河流中,但尺度以及分布受弯道环流结构影响较大。

Bend flow structure plays an important role in the evolution of natural river morphology.In order to further deepen the understanding of circulation structures and turbulence characteristics in the bends.Taking the continuous bend in Huanghuacheng reach of the Three Gorges Reservoir area as the research object,Acoustic Doppler Current Profiler(ADCP)was used to carry out prototype three-dimensional instantaneous velocity measurements.Scale distribution characteristics of bend circulation structures and turbulence structures were further analyzed.Results show the presence of macro-scale channel circulation structures in the Huanghuacheng reach.Due to the influence of local backwater and riverbed topography,measured vertical lines were characterized by full-depth circulation structure or double-circulation structure.Very large-scale turbulence structures still exist in the continuous curved rivers of the reservoir area,but their scale and distribution are greatly affected by the curved circulation structures.