闽江下游南北港分流比变化数值模拟分析

Numerical Simulation Analysis on Change of Diversion Ratio of North and South Ports in the Lower Reaches of the Minjiang River

为分析闽江下游南北港分流比变化过程以及河道演变对分流比的影响,在前人研究基础上,结合实测资料,通过数学模型,进行分流比变化模拟研究。结果表明:1997—2020年,闽江南北港分流比变化明显,2009年之前分流比变化程度强于2009年以后;1997—2020年,河床冲淤变化是南北港分流比变化的主要影响因素,导致50~200年一遇洪水北港分流比减小9.1%~10.6%,河道平面束窄对南北港分流比也有一定影响,影响幅度约3%。研究成果可为闽江下游南北港整治和保护管理及涉河开发建设等提供技术参考。

In order to analyze the change of the diversion ratio of north and south ports in the lower reaches of the Minjiang River and the influence of river channel evolution on this ratio,based on previous research,as well as measured data,this paper studies diversion-ratio change through mathematical models.According to the results,from 1997 to 2020,the diversion ratio of the north and south ports of the Minjiang River changed significantly,with the change before 2009 being greater than that after 2009.From 1997 to 2020,the change of riverbed erosion and siltation was the main factor influencing the change of the diversion ratio of the north and south ports.This results in a decrease of 9.1%~10.6%in the diversion ratio of the north port in the event of a flood once in 50~200 years.Moreover,the narrowing of the river plane also impacted the diversion ratio of the north and south ports to a certain extent,with an impact range of about 3%.The research results can provide technical references for improvement and protection management of the north and south ports in the lower reaches of the Minjiang River,as well as river-related development and construction.