Temporal network analysis of inter-organizational communications on social media during disasters: A study of Hurricane Harvey in Houston

The objective of this study is to model and analyze inter-organizational communication networks on social media to characterize the roles of organizations and situational information communication before, during and after disasters. Recent studies have shown that social media plays an important role in disasters, offering a participatory, collaborative and self-organized structure to communicate and disseminate situational information. Despite growing research on social media during disasters, little is known about the dynamic properties of inter-organizational networks and the roles of different organizations in communication networks on social media during disasters. This understanding is important for evaluating and improving collective action for disaster preparedness, emergency response, and recovery. To address this gap, this study presents a methodology for mapping and analyzing online organizational communication networks based on their interactions on twitter using the data obtained from Hurricane Harvey. The proposed method enables examining the network properties of online inter-organizational communication networks, unveiling the evolution of the roles of organizations within different phases of the disaster. The results show that: 1) during Harvey, government organizational users primarily generate information, while non-government organizational users mainly disseminate information, 2) during Harvey, most users in the cores of online organizational communication networks are from government organizations, 3) there are limited interactions among government and non-government organizational users before and after Harvey. The results provide insights into the roles of different types of organizations in online communication networks, helping make recommendations to improve inter-organizational communication in online social media to enhance disaster preparedness, responses, and recovery.