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该文通过座底式支架的ADV,对珠江河口底边界层的湍流进行了一个全潮25 h的观测,并利用该资料对湍流事件进行了研究,探讨了湍流事件特征量在潮内的变化。研究结果表明:(1)河口湍流事件受潮汐过程的影响,各特征量变化带有明显的半日分潮特征,且急流和憩流时刻差异显著。(2)对于动量事件,憩流时刻事件发生的次数多,但持续时间短,贡献率低,而急流时刻次数少,持续时间长,贡献率高;对于泥沙事件,憩流时刻次数少,但持续时间长且强度高,急流时刻次数多,但持续时间短且强度低。(3)湍流事件发生的时间约占总时间的40%,事件的平均持续时间分别为0.07 s(动量事件)和0.05 s(泥沙事件)。
In this paper, a turbulent flow at the bottom boundary layer of the Pearl River estuary was observed for 25 h by means of the ADV with a bottom bracket, and the turbulence events were studied by using this data. The variation of the turbulent event feature in the tide was discussed . The results show that: (1) The estuarine turbulent events are affected by the tidal process, and the variation of each characteristic has obvious semi-diurnal tidal characteristics, and there is a significant difference between the rapids and the break-off timings. (2) For momentum events, there are many occurrences of events during the break-off time, but the duration is short, the contribution rate is low, while the number of rapids is less, the duration is longer and the contribution rate is higher. For the sediment event, However, long duration and high intensity, the number of rapids at many times, but the short duration and low intensity. (3) The turbulent events took about 40% of the total time, and the average durations of the events were 0.07 s (momentum event) and 0.05 s (sediment event) respectively.