磨刀门拦门沙发育演变影响因素分析

Analysis on Influencing Factors of Modaomen Estuary Sandbar Development and Evolution

磨刀门为西江干流的主要出海口,泄洪、输沙量均居珠江八大口门之首,是唯一直面外海的口门。磨刀门河口是一个受制整体又牵动整体的多场耦合、人为干扰严重的复杂整体系统,其口外拦门沙演变是聚合多因子耦合、多向输沙的复杂问题。传统研究基于实测资料分析、数值模拟、物模试验及遥感信息技术基础上探究拦门沙演变规律,割裂了不同因子耦合与演变响应,难以揭示拦门沙发育内因。在总结已有研究成果基础上,分析磨刀门河口水动力及其伴生过程对拦门沙演变的影响,探求不同因子耦合与演变响应机制,甄别影响拦门沙演变的关键因子。研究发现:在珠江河口系统的动力结构下,拦门沙是口门外径潮平面环流结构相互作用的结果,而枯季的波浪滩面掀沙及沿岸流输沙,对其的形成与发育产生一定的影响。

As the main marine outfall of Xijiang River,Modaomen Estuary's flood and sediment ranks first place among the eight estuaries of Pearl River,also is the only estuary which leading to open seas.Modaomen Estuary is a complicated and integral system which contains multi-field coupling and serious human intervention,its outside sandbar evolves into multi-factor coupling polymerization and multi-transport complex problems.Most traditional research is based on experimental data analysis,numerical modeling,physical model test and remote sensing information to explore bar evolution rule.It only separates the different factors of mutual coupling and response of the evolution,while difficult to reveal the internal cause of bar.Accordingly,based on summarizing current research results,this paper analyzed the hydrodynamic force of Modaomen bar and its associated process how to impact bar evolution process,meanwhile explored different factors of mutual coupling,evolution of response mechanism,and the key factor affecting the evolution of bar screening.The study found that,with the dynamic system of Pearl River Estuary,the bar's formation was the result of estuary diameter plane structure interaction with tidal circulation.In dry season,due to the beach face lifts sand and coastal wave forms to sediment,to modify the outer form would be impacting its formation and development in a certain way.