赤潮发生和蔓延的动力机制数值模拟

Numerical simulation of the dynamic mechanism of the occurrence and spread of HAB

海洋中发生的赤潮不是单纯的生物生态问题 ,而是在海洋动力环境条件控制下的生物生态问题 .对 4种情况进行数值模拟来证明动力条件对赤潮的发生、蔓延所起的重要作用 .这 4种情况是 :( 1 ) 1 998年春实际发生在香港海域的赤潮的生消全过程 ;( 2 )改变潮差后的赤潮生消全过程 ;( 3)改变流场的扩散强度后的赤潮生消全过程 ;( 4 )通过工程措施改变海区的周边地形来控制赤潮的蔓延途径 .这些模拟结果表明海洋的动力条件不仅对赤潮的蔓延发挥输运作用 ,而且对赤潮的形成有影响 。

The occurrence of HAB is not a single biological and ecological problem. It is one under the control of marine dynamic environment. The numerical simulation for four cases manifests the important function of dynamic condition in the occurrence and the spread of HAB. Those cases are (1) the HAB real occurred in the Hongkong sea area in March to April of 1998. (2) Decreasing tidal amplitude for two third only but without change for other parameters. (3) Changing the diffusion term only but without change for other parameters. (4) With the marine construction, changing the environment topography only but without change for other parameters. Those simulation results manifest that the dynamic condition plays the function not only in the movement of materials but also in the occurrence of HAB. It could control the occurrence of HAB sometimes.