磨刀门咸潮上溯对河口拦门沙地形变化的响应研究  

Study on response of saltwater intrusion to topographic changes of mouth bar in Modaomen Estuary

作　　者：林中源 胡晓张 邹华志 张光 陈睿智 唐琦 LIN Zhongyuan;HU Xiaozhang;ZOU Huazhi;ZHANG Guang;CHEN Ruizhi;TANG Qi(Key Laboratory of Pearl River Estuary Regulation and Protection of Ministry of Water Resources,Guangzhou 510611,China;River and Coast Research Institute,Pearl River Water Resources Research Institute,Guangzhou 510611,China;School of Marine Sciences,Sun Yet-Sen University,Zhuhai 519082,China)

机构地区：[1]水利部珠江河口治理与保护重点实验室,广东广州510611 [2]珠江水利科学研究院河流海岸研究所,广东广州510611 [3]中山大学海洋科学学院,广东珠海519082

出　　处：《水资源保护》2024年第5期104-111,共8页Water Resources Protection

基　　金：广东省水利科技创新项目(2023-01);水利部重大科技项目(SKS-2022005)。

摘　　要：采用磨刀门河口拦门沙地形变化前后的2005年和2020年实测地形资料,基于FVCOM三维数值模型,对比分析了咸潮上溯对河口拦门沙地形变化的响应,并探讨了拦门沙萎缩对盐分输运的影响机制。结果表明:拦门沙萎缩导致磨刀门水道各取水口表、底层盐度差增大,水体层化程度增强,下游至上游层化增强程度逐渐减小,广昌泵站势能异常最大值增大25.2 J/m^(3),马角水闸、平岗泵站、竹洲头泵站分别增大8.3、2.9、0.2 J/m^(3);拦门沙萎缩后未改变磨刀门水道咸潮上溯规律,半月潮周期盐度峰值依然出现在小潮后的中潮期;拦门沙对咸潮上溯有较大阻碍作用,底层15 psu等盐度线最大上溯距离向陆推进5.1 km,对于取水更为重要的表层0.5 psu等盐度线最大上溯距离向陆推进2.9 km;稳定剪切盐通量显著增大是拦门沙萎缩后咸潮上溯加剧的主要原因,并叠加潮汐震荡盐通量增大的影响。Using measured terrain data from 2005 and 2020 before and after topographic changes of mouth bar in the Modaomen Estuary,a FVCOM three-dimensional numerical model was used to compare and analyze the response of saltwater intrusion to topographic changes of mouth bar,and to explore the impact mechanism of mouth bar shrinkage on salt transport.The results showed that the mouth bar shrinkage resulted in increases in the salinity difference between the surface and bottom layers of each water intake in the Modaomen Waterway,increases in the degree of water stratification,and gradual decreases in the degree of stratification enhancement from downstream to upstream.The maximum potential energy anomaly of Guangchang Pump Station increased by 25.2 J/m^(3),while Majiao Water Lock,Pinggang Pump Station,and Zhuzhoutou Pump Station increased by 8.3,2.9,and 0.2 J/m^(3) respectively.The shrinkage of the mouth bar did not change the upward trend of the saltwater intrusion in the Modaomen Estuary,and the peak salinity of the half-moon tide cycle still appeared in the middle tide period after the small tide.The mouth bar has a significant hindering effect on the upstream movement of the saltwater intrusion.The maximum upstream distance of the 15 psu iso-salinity line in the bottom layer is pushed towards the land by 5.1 km,while the maximum upstream distance of the 0.5 psu iso-salinity line in the surface layer,which is more important for water intake,is pushed towards the land by 2.9 km.The significant increase of stable shear salt flux is the main reason for the saltwater intrusion after the shrinkage of mouth bar,on top of which is the influence of tidal oscillation salt flux increase.

关 键 词：咸潮上溯 河口拦门沙 FVCOM三维数值模型 盐通量 磨刀门 

分 类 号：P731.12[天文地球—海洋科学]