环渤海排污口临近海域水交换能力研究

The Water Exchange of the Adjacent Seas of the Drain Outlets into the Bohai Sea

将环渤海主要入海排污口按位置划分至31个归并点,并定义了影响距离的概念,用于衡量各归并点所代表的排污口临近海域的水交换能力。在渤海三维水动力模型的基础上,利用质点追踪的方法研究了各归并点的30d影响距离。此外,通过在夏季(7月)大潮、夏季小潮、冬季(1月)大潮、冬季小潮4个时间段释放质点以研究季节和潮汐对30d影响距离的作用。结果表明:不同排污口邻近海域的水交换能力差异显著;与小潮相比,大潮期间排污口邻近海域水交换能力更强,因此大潮期间排污有助于污染物扩散;不同季节污染物扩散方向不同,与季风有关。据此海洋环境保护部门可根据不同海区水交换能力的差异调整排污量。

The major drain outlets around the Bohai Sea were divided into 31 attaching points. Mean- while, a new concept, influence distance, was introduced to quantify the water exchange ability of the offshore realm adjacent to each attaching point which represents drain outlets nearby. Based on the three-dimensional numerical ocean model of Bohai Sea, Lagrangian particle tracing method was applied in the estimation of a 30-day influence distance of all attaching points. Besides, in order to explore the seasonal and tidal effects on the 30-day influence distance, 4 typical periods （spring tide and neap tide in summer and winter respectively） were selected to release particles. In conclusion, water exchange ability enhances during a spring tide period and due to significant influence of East Asian monsoon on the water exchange ability, effluent discharge plans should take seasonal variability into consideration.