Social Cohesion: Mitigating Societal Risk in Case Studies of Digital Media in Hurricanes Harvey, Irma, and Maria

Natural disasters affect thousands of communities every year, leaving behind human losses, billions of dollars in rebuilding efforts, and psychological affectation in survivors. How fast a community recovers from a disaster or even how well a community can mitigate risk from disasters depends on how resilient that community is. One main factor that influences communities' resilience is how a community comes together in times of need. Social cohesion is considered to be"the glue that holds society together, which can be better examined in a critical situation. There is no consensus on measuring social cohesion, but recent literature indicates that social media communications and communities play an essential role in today's disaster mitigation strategies.This research explores how to quantify social cohesion through social media outlets during disasters. The approach involves combining and implementing text processing techniques and graph network analysis to understand the relationships between nine different types of participants during hurricanes Harvey, Irma, and Maria. Visualizations are employed to illustrate these connections, their evolution before, during, and after disasters, and the degree of social cohesion throughout their timeline. The proposed measurement of social cohesion through social media networks presented in this work can provide future risk management and disaster mitigation policies. This social cohesion measure identifies the types of actors in a social network and how this network varies daily. Therefore, decisionmakers could use this measure to release strategic communication before, during, and after a disaster strikes, thus providing relevant information to people in need.