珠江三角洲西、北江干流水道水沙净输运机制分析

Analysis on Transport Mechanism of Water and Suspended Sediment in Xijiang River and Beijiang River of the Pearl River Delta

珠江三角洲西、北江干流水道是三角洲主要的输水输沙通道。该区域洪潮交叠、海陆交汇,水流特性复杂。对珠江三角洲西、北江干流水道枯季大小潮实测数据进行物质输移量分解,计算分析区域余流值及悬沙输运机制。结果表明:研究区域受径流影响程度超过潮流,而北江干流受潮流影响程度超过西江干流;悬沙输运中,欧拉余流悬沙输移为区域悬沙输移的最主要控制因素,斯托克斯漂移、潮汐与悬沙含量潮变化相关项、垂向净环流对悬沙输移也有一定影响。

The main channels in Xijiang River and Beijiang River are mainly used for transporting water and sediment.Those two rivers are affected by runoff and tide,mechanism analysis will help us to analyze the contribution of different components to water and sediment transport.Based on the measured tide data during dry season in the main channels of Xijiang River and Beijiang River,this paper decomposed the material transport to calculate and analyze regional residual current value and suspended sediment transport mechanism.The results showed that the Xijiang River was more affected by the runoff and the Beijiang river was more affected by tide.The main factor affecting the suspended sediment transport was Euler residual current.The Stokes drift,the tidal pumping effect and the vertical gravitational circulation had an impact on suspended sediment transport as well.