[Numerical analysis on pollutant decline in the emergency of water pollution in Three Gorges]

The water self-clarification ability in the reservoir area is much lower and the risk of the emergency of water pollution is more serious after the accomplishment of water storage in Three Gorges. This paper presented a hydrodynamic model for emergency of water pollution by the investigating the water states in Three Gorges, validated the veracity of the model by comparing flow velocity on the selected cross sections between the computed and measured data, and introduced numerical method to give visual show of the pollutant' s diffusion and to study the movement roles of pollutant after an accident. Further, analyzing the actual instance and characteristic, the decay process of pollutant was numerically simulated after controlling polluting source and taking decontaminating measure in river, and the effect of emergency measure was analyzed and discussed. It is more helpful for emergency to make a scientific decision in the respect of selecting control areas and methods after a pollution accident, putting forward a new way to effectively prevent and control water pollution.