中文摘要：

珠江河口磨刀门咸潮入侵有逐年增强趋势,其发生频率越来越高。此文采用有限体积近岸海洋模型（FVCOM）建立了珠江河口三维咸潮水动力数学模型,并采用实测潮位、盐度和流速对模型进行了率定和验证,表明该模型较好地反映珠江河口,特别是磨刀门咸潮上溯的水动力情况。采用已率定的FVCOM模型,分别对疏挖磨刀门拦门沙以及建设人工潜坝之后的工况进行数值模拟,研究了控制工程措施对咸潮上溯的影响。结果表明,疏挖拦门沙后,5‰盐度等值线的上溯最远点向内陆推进了2.5 km,咸潮入侵程度有所加剧;而建造距河底3 m高的人工潜坝后,5‰盐度等值线的上溯最远点向外海退缩了1.3 km,咸潮入侵程度有所减弱。该研究对压咸措施有一定的指导意义。

英文摘要：

The salinity intrusion to Modao watercourse in Pearl River Estuary has strengthening trend year by year,this study focus on applying a three dimensional finite-volume coastal ocean model（FVCOM） for simulation the flow velocity,tidal levels and salinity field in the Pearl River estuary.The results show the FVCOM can be applied for the simulation of salinity intrusion of the Pearl River estuary successfully.The calibrated model was then applied to simulate the salinity and flow velocity field after removing the sandbar located on the estuarine mouth of Modao watercourse and after hypothesis to building a submerged dam in the Modao watercourse.After removing the sandbar,the salinity becomes a little greater at the same location,the advective distance of 5‰ salinity becomes a little larger and the salinity intrusion is a little more serious.After building a submerged dam,the salinity will keep almost unalterable at the same location and the advective distance will be drawn back about 3km of the 0.5‰ contour line in the Modao watercourse.This research will supply some references for assessing the effects of controlling engineering measures on saltwater intrusion.