The physical and chemical processes of polycyclic aromatic hydrocarbons (PAHs) are coupled with their ecological dynamic processes by using Delft3D model in the Hulushan Bay, Dalian. Based on in-situ monitoring data and previous references, the characteristic parameters for the ecological dynamics processes of PAHs are set and the corresponding simulated work is carried out. Here, the growth rate of phytoplankton is selected as an indicator of ecosystem health in coastal waters, and the numerical simulation results of PAHs concentrations are fitted with the dynamics response equation of the growth rate of phytoplankton to quantitatively evaluate the effect of PAHs on marine ecosystems. The result shows that when the sewage outfall is located at such a place with deep water, fast flow rate and strong hydrodynamic condition, it will benefit the diffusion of PAHs, and thus improve the water quality. On the contrary, it will result in the serious enrichment of PAHs in the Hulushan bay. In addition, the enrichment of PAHs has a significant influence on the ecological environment in the Hulushan Bay. The poor hydrodynamic conditions lead to that the reduction of 18% in the growth rate of phytoplankton. Finally, spatial GIS analysis demonstrates that the reduction in the growth rate of phytoplankton does not agree with the spatial distribution of PAHs concentrations well, reflecting the dynamic complexity and ecological stability of the ecosystem in the Hulushan bay.%利用生态动力学模型Delf3D,对大连葫芦山湾海域多环芳烃(PAHs)在海洋中的理化及生态动力学过程进行耦合,并以大连葫芦山湾实际监测数据及相关文献资料为基础,确定了一套适用于该近岸海域PAHs生态动力学过程的特征参数,模拟研究了PAHs在近岸海域生态动力学过程.以浮游植物生长率作为指示近岸海域生态系统健康程度的指标,将PAHs含量的数值模拟结果与浮游植物生长率的动力学响应方程相拟合,定量的评估了PAHs对海洋生态系统的影响.结果显示:排污口选址于水深大、流速快、水动力强处,对PAHs污染物扩散、水质改善具有显著作用,反之造成PAHs大规模富集.PAHs富集作用对该湾生境影响较显著,湾顶水动力作用微弱,浮游生物生长率削减度高达18%.ArcGIS分析显示,浮游生物生长率削减程度与PAHs时空分布并不完全一致,体现海湾生态系统的动力复杂性与结构稳固性.
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