乐清湾海洋环境季节特征及水交换过程研究

Seasonal characteristics of marine environment and water exchange in Yueqing Bay

基于4个航次的实测资料,分析乐清湾的温(度)盐(度)、潮汐、潮流和余流等海洋环境季节分布特征,并采用环境流体动力学模型研究乐清湾的水交换过程,提出一个计算海湾水体平均置换率的简单公式,以直观描述湾内水体与湾外水体交换的过程特征。结果表明,乐清湾的水交换能力与湾内温(度)盐(度)水平及断面分布特征一致,从口门到湾顶,水交换能力差别较大,连屿至打水山断面以南的水体基本1个月可完全交换,连屿至打水山断面以北的水体2个月仍然无法交换到湾口水平。

Based on observed data from four cruises, the seasonal distributions of temperature, salinity, tides, currents, and residual currents of Yueqing Bay were analyzed. The EFDC was used to study the water exchange processes in the bay. A simple formula, which can directly describe the exchange process of the water bodies inside and outside the bay, was proposed to compute the average exchange rate. The results show that the water exchange capability is in accordance with temperature, salinity, and distribution characteristics of sections. The water exchange capability varied significantly from mouth to top of the bay. The water bodies to the south of the Lianyu- Dashuishan section could be fully exchanged, while those to the north could not be exchanged as well as that at the bay mouth within two months.