In this paper, the turbulence characteristics of the tidal flow in the Qiantang River, China, the world-famous Qiantang bore, are studied. A detailed field observation at the Yanguan section of the Qiantang River was ...In this paper, the turbulence characteristics of the tidal flow in the Qiantang River, China, the world-famous Qiantang bore, are studied. A detailed field observation at the Yanguan section of the Qiantang River was carried out during the spring tide in October 2010 with a continuous collection of high frequency turbulence data. The data analysis shows that the hydrodynamic processes are characterized by a strong tidal bore. Statistics of the turbulence such as the probability distributions of the turbulent components, the variance terms and the covariance terms are found consistent with those of previous studies of estuaries without the tidal bore. However, along the vertical profile, the distributions of all variables become more scattered downwards. The horizontal turbulence fluctuations are of a similar magnitude while the vertical turbulence has a fluctuation magnitffde about 1/3 of that of the horizontal turbulences. The fluctuation strengths and the Reynolds stresses are much larger than those of other estuaries when the bore arrives. The bottom shear stress varies periodically with the tides, less than 0.44 N/m2 during the ebb but is increased drastically at the bore arrival, with the maximum being 0.92 N/m2. A good linear relationship is found between the bottom shear stress and the bottom suspended sediment concentration.展开更多
基金Project supported by the Natural Natural Science Foundation of China(Grant No.51379190,41376099)the Ministry of Water Resources’special funds for scientific research on public causes(Grant No.201001072)the Zhejiang Province Key Science and Technology Innovation Team Building Project(Grant No.2010R50035)
文摘In this paper, the turbulence characteristics of the tidal flow in the Qiantang River, China, the world-famous Qiantang bore, are studied. A detailed field observation at the Yanguan section of the Qiantang River was carried out during the spring tide in October 2010 with a continuous collection of high frequency turbulence data. The data analysis shows that the hydrodynamic processes are characterized by a strong tidal bore. Statistics of the turbulence such as the probability distributions of the turbulent components, the variance terms and the covariance terms are found consistent with those of previous studies of estuaries without the tidal bore. However, along the vertical profile, the distributions of all variables become more scattered downwards. The horizontal turbulence fluctuations are of a similar magnitude while the vertical turbulence has a fluctuation magnitffde about 1/3 of that of the horizontal turbulences. The fluctuation strengths and the Reynolds stresses are much larger than those of other estuaries when the bore arrives. The bottom shear stress varies periodically with the tides, less than 0.44 N/m2 during the ebb but is increased drastically at the bore arrival, with the maximum being 0.92 N/m2. A good linear relationship is found between the bottom shear stress and the bottom suspended sediment concentration.
