基于三维水动力水质数值模型的象山港排污策略研究

本文以象山港（半封闭港湾）为研究对象，采用Delft 3D软件建立三维水动力数值模型，对其潮位、潮流、温度、盐度的时空变化进行验证分析，计算结果与实测结果基本吻合，表明该模型能够较好地模拟象山港海域的水动力特征。为进一步研究象山港内污染物的迁移转化过程，在上述水动力模型的基础上构建三维水质模型，水质模拟结果与实测数据吻合良好，可以反映水质的变化趋势。利用验证后的水质模型，针对排污口的落潮排放、排放量减少和排污口整合3种排污策略进行模拟计算，分析排污口对象山港水质变量的影响程度。模拟结果表明，象山港水质环境受排污口影响明显，3种排污策略均可以直接降低港内DIN浓度，但不同的工况表现出不同的影响特征。

An investigation of the pollutants discharge control strategies in Xiangshan bay based on 3D hydrodynamic and water quality numerical modelling

A numerical model based on Delft 3D, an open source three-dimensional hydrodynamic model, was built to simulate the temporal and spatial distribution of tidal level, tidal current, temperature and salinity in Xiangshan bay. Calculated results were found to match the measured data closely, which demonstrated the model was able to simulate the hydrodynamic characteristics of Xiangshan bay accurately. Based on the validated flow model, a water quality model was built to investigate the migration and transformation process of pollutants in Xiangshan bay. The simulation results were again found to match with the measured data and the model is capable of reproducing the variation trend of the most water quality variables in Xiangshan bay. The verified water quality model was then applied to analyze the influence of the sewage outlets on the water quality variables in Xiangshan bay considering the timing of the discharge (during ebb tide), variation of discharge rate and layout of the sewage outlets. The simulation results showed that the water quality environment of Xiangshan bay was clearly affected by the locations of sewage outlets and the three design scenarios considered could all directly reduce the DIN concentration in the bay with different scenarios shown different influencing characteristics.