Qualitative simulation of the panic spread in large-scale evacuation

A small amount of literature has been produced on the study of panic spread in a large-scale emergency evacuation, especially that which involves rescue guidance. In a large-scale evacuation action, there are complicated interactions between people and the disaster environment, and it is very difficult to present such interactions in quantitative functions or specific values. In this paper, a qualitatively simulated approach to model and study the panic spread is proposed. First, the internal structure of the evacuation system is described and various internal and external phenomena related to the change of evacuees’ behaviors in the evacuation process are qualitatively interpreted. Based on the qualitative knowledge, a qualitative simulation model of a large-scale evacuation system is established. The calculation results of inverse group matrix verify the rationality and stability of our model. According to the implementation of a series of scenarios with different input, some uncertainty factors that can affect the panic spread in the evacuation process are analyzed, in which the spread of disaster, the rescue guidance, and the normal emotional evacuees are mainly considered. This model reproduces a well-known phenomenon in crowd evacuation, namely “fast is slow”, and confirms that the severity of disaster exponentially positively correlates with the panic spread, and the effectiveness of rescue guidance is influenced by the leading emotion in the crowds as a whole.