Characteristic and Influential Factors of Pollution Zone in the Lower Reach of Minjiang Tidal River

The lower reach of Minjiang River, which passes through the Fuzhou city, is in the tidal area. A Two-Dimensional hydrodynamic and water quality model is developed. Taking Wukong sewage outfall as an example, the characteristic of pollution zone which is visualized by the contour of concentration is investigated, and the influential factors are also analyzed. It shows that the longest upstream pollution zone appears near the fastest flood moment, the longest downstream one appears near the ebb moment, the widest pollution zone occurs near the high or low water stand moment. The factors such as pollutant load, pollutant decaying coefficient and longitudinal diffusion coefficient are sensitive to the range of the pollution zone.