Abstract: The aim of this research is to mitigate emergencies in high-risk operation of water conservancy projects and to control the impact of emergency events.First of all,the diagram of evolution mechanism of emergency is obtained via analyzing the influencing factors of safety risks in high-risk operations.The cusp catastrophe model for high-risk operation emergency of water conservancy projects is then established based on the catastrophe theory with internal motivation and external incentives as control variables and construction safety dynamics as state variable. The formation process of emergency event is examined using the model, and the role of splitting factors and regular factors before and after emergencies and the trajectory of event evolution are expounded.Moreover,six safe statuses,inclusive of safe operations(two types), external hazard-hidden operations, internal hazard-hidden operations, and dangerous operations(two types),are summarized;corresponding preventive measures, control measures,and emergency measures are put forward.The research results suggest that enhancing the quality of workers is a key factor in avoiding emergencies, and the behavior of managers is extremely influential before and after the events. The present model is a further theoretical attempt for the safety guarantee of high-risk operations in hydraulic engineering.

Key words: hydro-project, high-risk operation, emergencies, evolution mechanism, cusp catastrophe model, management and control measures