Laboratory measurements of sediment flux and bed level evolution in the swash zone
Laboratory measurements of sediment flux and bed level evolution in the swash zone
复制标题
斜流带沉积物通量和床位演变的实验室测量
DOI：
10.1142/s0578563416500042
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发表时间：
2016
影响因子：
2.4
通讯作者：
Akio Okayasu
中科院分区：
文献类型：
--
作者：
Lianhui Wu;Dejun Feng;Takenori Shimozono;Akio Okayasu
对溃坝波作用下桑迪细坡冲淤带泥沙输移进行了详细的室内试验研究。采用新开发的泥沙输运测量系统，分别基于粒子图像测速技术（PIV）和消光法，以0.53 mm的垂直分辨率同时测量泥沙浓度和输运速度。将浓度资料与流速资料相结合产生泥沙通量，并用于研究溃坝波作用下冲流区的泥沙输移特性。实验中发现，沙粒随流性较好。最大流速与最大浓度在初始上冲阶段存在明显的相位差。最大浓度在不同海拔高度间差异显著。近岸通量远大于近海通量，近床通量远大于高海拔通量。净输运在近岸靠近底质处，在中层向岸，在上层几乎为零。由床面演变计算的质量变化与由测量系统得到的净输沙量之间的测量误差小于20%。
A detailed laboratory study of swash zone sediment transport under dam-break waves on a fine sandy slope was carried out. A newly developed sediment transport measurement system was applied for simultaneous measurement of sediment concentration and transport velocity with a vertical resolution of 0.53 mm based on particle image velocimetry (PIV) and a light extinction method, respectively. Concentration data were combined with velocity data to produce sediment flux and were used to investigate the characteristics of sediment transport in the swash zone under dam-break waves. It was found that sand particles followed the flow well in the experiment. Phase difference between the maximum velocity and maximum concentration in the initial uprush was obvious. The maximum concentration varied significantly between different elevations. The onshore flux was much larger than the offshore flux, and the flux near the bed was much larger than that at the higher elevations. The net transport was offshore close to the bed, onshore in the middle layer, and almost zero in the upper layer. The measurement error between the mass change calculated from bed form evolution and the net sediment transport obtained from the measurement system was smaller than 20%.