珠江口蕉门南水道枯季时局部高盐度区形成与机理分析  

Formation of a local high-salinity zone in South Jiaomen Waterway of Lingdingyang Estuary and its associated mechanisms

作　　者：刘永金[1] 龚文平[2] 

机构地区：[1]湖北交通职业技术学院,湖北武汉430079 [2]中山大学海洋学院,广东广州510275

出　　处：《海洋工程》2017年第3期105-111,共7页The Ocean Engineering

基　　金：广东省重点基金(2014A030311046)

摘　　要：采用ROMS模型研究了珠江口蕉门南水道枯季时的局部高盐度现象。表明这一现象在大潮期发育显著,而小潮期则不明显。从动力机制上解释了这一现象的成因,揭示其形成原因为大潮期的平流输运强,涨潮时的潮程远大于凫洲水道的长度,以及大潮期径流相对较小,有利于虎门的高盐度水体输运至蕉门水道。此外,大潮期由于洪奇沥与横门来的淡水在涨潮期向北输运而导致蕉门南水道口门处盐度较低。并进一步分析了这一现象的存在对蕉门南水道水体分层、河口环流及物质输运的意义。Utilizing ROMS model, this study investigates the formation of a local high-salinity zone in South Jiaomen Waterway, Lingdingyang Estuary in the dry season. The results show that this phenomenon occurs more obviously during spring tides, while in neap tides, the local high-salinity zone is not distinct. The mechanisms behind such a phenomenon are due to three reasons： 1 ） the tidal excursion during spring tides is significantly longer than that during neap tides, favoring the transport of high-salinity water from Humen Outlet to Jiaomen Outlet via Fozhou Waterway; 2） the runoff from upstream during spring tides is less than that during neap tides, and does not play a role in impeding the transport of high-salinity water from Humen to Jiaomen. 3） the salinity at the mouth of South Jiaomen Water way is relatively low due to the advection of fresher water from the Hongqili and Hengmen during flood tides. The existence of such a local high-salinity zone is significant in modulating the estuarine circulation, stratification in the water column, thus imposing an effect on oxygen and nutrient dynamics in the waterway.

关 键 词：珠江口 逆盐度梯度 河口环流 水体分层与混合 

分 类 号：TV148.4[水利工程—水力学及河流动力学]