Julius Bañgate - Multi agent modelling of seismic crisis

Evacuations are necessary during earthquake crisis to mitigate and avoid risks of exposure to hazards that can cause injury or death. Evacuation are social in nature. This is mainly because the main agents in evacuations are people who possess highly evolved social strategies for coping with danger. Social attachment theory posits that proximity seeking behaviours are activated during danger. In this situation people seek attachment figures. Attachment figures include familiar people, places, object, etc. The presence of attachment figures promotes the feeling of calm and safety. Conversely, their absence result in anxiety and flight. This means for example that during disasters individuals may seek family members, before evacuating. Also, this explains the behaviour why people gather personal property before heading to familiar exits and places, or follow groups/crowds, etc. 

In this framework, a multidisciplinary approach – based on social, geoscience, spatial and computer sciences – is proposed to simulate individuals’ behaviours after an earthquake in the city of Grenoble, France. For this purpose, SOLACE, a multi agent model on crisis evacuations was developed to answer eight key questions (Q1 to Q8) that can explain the nature and impact of human evacuation behaviour modulated by social attachment. The effect of several parameters on the number of arrivals in safe areas was observed: social attachment (Q1); knowledge (Q2); number of close bonds (Q3); time of day (Q4); presence of disability (Q5); presence of casualties (Q6); earthquake intensity (Q7); and radius of danger zones around buildings (Q8).  

The results of the experiments point to the importance of social interactions during evacuations. The behaviours of individuals are significantly affected by their social environment that responds to the challenges imposed by the physical environment produced by earthquake disasters. The capacity and tendency for social interaction are inherent in humans and need to be considered in evacuations. It was shown that social attachment is important because it can facilitate saving more lives during earthquake disasters.

The first and main contribution of the research is to add to arguments stressing the importance of human behaviour and the social dynamics that emerge during crisis evacuations. The second major contribution of the study is SOLACE, the multi agent-based model for earthquake evacuation implemented using social attachment. The third major contribution is that the research supports the benefit of using accurate spatial data in dynamic multi agent-based models.