Early Warning of Sudden Water Pollution Accident Risks Based on Water Quality Models in the Three Gorges Dam Area

In recent years, sudden water pollution accidents have frequently occurred and seriously endangered people’s drinking water safety. Early warnings for water pollution accidents has become the core work for emergency response and sparked substantial research. However, risk assessments for different water receptors still needs to be solved for the early warning of water pollution accidents. This paper proposes a new early warning assessment method based on water quality models for different receptors, divided into the water source area (including drinking water source area and agricultural water use area) and the non-water source area. The constructed method was applied to the Three Gorges Dam area in China to simulate a phosphorus leakage accident caused by a traffic accident. Based on the EFDC model, the migration evolution process and the distribution change characteristics of phosphorus were simulated. Accordingly, the different risk levels of zones between the incident site and the downstream drinking water source area were obtained. The application results show that the risk warning system for sudden water pollution accidents based on the water quality model proposed in this paper can be applied to provide scientific support for the emergency response of sudden water pollution accidents.