Three-dimensional Water Quality Mathematical Model Updating Its Eastern Zhejiang Coastal Waters Water Quality Simulation

Offshore areas of Zhejiang Province are mostly shelf seas, so tide and flow played an important role in the controlling of ocean dynamic. Based on the previous achievements, this study analyzed the data of hydrology and water quality of Zhejiang offshore areas, and determined the boundary conditions for the mathematical model based on hydrological conditions. Then, the FVCOM(Finite Volume Coastal Ocean Model) model was developed and rated using the data of underwater topography, tide level and tidal current. And the three-dimensional water quality model was verified according to the monitoring data of water temperature and pollutants concentration in offshore areas of Zhejiang Province. Finally, the effects of some marine projects in Zhejiang offshore areas onto local flow and water quality were simulated.This study was conducted based on the built three-dimensional tide and water quality numerical models for coastal regions of Zhejiang, and the pre-and post-processing module of the SMS software. The high-quality, non-triangular structure grids were generated, and the results of FVOCM were transferred to the SMS platform for flow analysis and post-processing. Then, combined with google earth tool, three-dimensional graphics display system for tidal current field and concentration field was built. Additionally, according to the characteristics of the regional tide flow, the module for bottom resistance parameter calculation was developed to adapt to the target area.the established modified model could well simulate the coastal tide and three-dimensional flow of Zhejiang Province. The model also provided reliable tidal flow analysis for preliminary research of the local ocean engineers, and improved the accuracy and depth of the simulation. Besides, the three-dimensional water quality model modefied from FVCOM, was used for the calculation of three-dimensional water quality of Zhejiang Province. After further investigation, the model could be more perfect and would set a solid foundation for the further development.