ABSTRACT Field observations were conducted during relatively mild wave conditions at a dissipative barred sandy beach to investigate the cross-shore sediment dynamics from the inner surf zone to the offshore side of the outer bar. Fluorescent sand tracers of five different colors were placed on the seabed at different cross-shore locations, and sand core samples were extracted respectively 11 and 20 days after the placement of tracers. Moreover, nine cross-shore bathymetric/topographic beach surveys were conducted, and the water level, wave, and wind conditions were observed. The objective of this research was to investigate the mechanisms of the on- and offshore-directed sediment transport during the inner- and outer-bar accretion events. The analyzed results revealed that at the inner surf zone, the sediment was dominantly transported in the onshore direction. The sediment was also transported offshore-ward due to the undertow; however, this occurred until the offshore end of the trough region. Overall, the outer bar shape affected the on-offshore sediment transport rate. The sediment movements in the onshore region and offshore region of the outer bar were not related; however, the outer bar was formed with the sediments from both the inner- and outer-bar regions.

中文翻译：

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在近岸区增生波条件下使用示踪剂观察到的沉积物颗粒运动

摘要 在消散性沙坝的相对温和的波浪条件下进行了实地观察，以研究从内海浪区到外沙坝近海侧的跨岸沉积动力学。将五种不同颜色的荧光砂示踪剂放置在不同跨岸位置的海床上，分别在放置示踪剂后11天和20天提取砂芯样品。此外，还进行了九次跨岸测深/地形海滩调查，并观察了水位、波浪和风况。这项研究的目的是研究在内部和外部酒吧吸积事件期间向内和近海定向沉积物输送的机制。分析结果表明，在内部冲浪区，沉积物主要向陆上输送。由于底流，沉积物也被输送到近海区；然而，这一直发生到海槽区域的近海端。总体而言，外条形状影响了近海沉积物的输送速率。外坝陆上区与近海区的泥沙运动无关；然而，外滩是由内滩和外滩的沉积物形成的。