A Message Reduction Method Based on Geographical Information in Initiative-Evacuation Induction Using Social Graphs

In Japan, tsunamis and landslides are frequently caused as secondary disasters after earthquakes, and early evacuation is an important issue to reduce the damage. In this study, we propose a method to reduce the time required to complete evacuation using social graphs and to reduce the number of messages for evacuation based on geographical information. We propose a method to speed up the evacuation completion time and reduce the number of messages by setting an evacuation target area and evacuating only the targets (nodes) in the area. n Relaying an evacuation order only when there is a node in the evacuation area ahead of the node, the method speeds up the evacuation completion time and reduces the number of messages. The evaluation results confirmed that the proposed method was able to reduce the number of messages in the evacuation while maintaining a faster evacuation completion time compared to the case where all nodes outside the evacuation target area relayed the evacuation order and the case where no relay was performed.