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New Research Analyzes Millions of Twitter Posts During Hurricanes to Understand How People Communicate in a Disaster

New study suggests that monitoring social media during hurricanes could help communities better plan for and mitigate the impacts of climate change

In the face of a potentially disastrous storm like Hurricane Ida, people take to Twitter and other social media sites to communicate vital information. New research published in the journal Risk Analysis suggests that monitoring and analyzing this social media “chatter” during a natural disaster could help decision makers learn how to plan for and mitigate the impacts of severe weather events in their communities.  

Gabriela Gongora-Svartzman from Carnegie Mellon University’s Heinz College of Information Systems and Public Policy and Jose E. Ramirez-Marquez from the Stevens Institute of Technology performed an analysis of more than 6 million Twitter posts over time during three major hurricanes that made landfall in 2017: Harvey (Texas), Irma (Florida), and Maria (Puerto Rico). The goal of their study was to develop and test a new method for measuring social cohesion, an important factor in a community’s resilience.

Social cohesion has been described as “the glue that holds society together.” It affects how a community comes together in times of need. Social cohesion can help reduce the number of vulnerabilities experienced by a community during a disaster and reduce the time it takes to rebuild. The stronger the social cohesion, the more resilient a community is.

“If we measure and understand social cohesion within communities, then we can seek to increase cohesion - through policies, community programs, and other strategies - which in turn will increase the resilience of communities,” says Gongora-Swartzman. “People in a more resilient community are more willing to volunteer and help each other during a disaster. A more resilient community is also better informed, therefore knowing who to ask for help, what resources are available, and how to help during a disaster.”

There are several visualizations in the study that illustrate the metrics that are combined to create a measurement of social cohesion. One of these metrics is information dissemination. This refers to the intensity of tweets, or communication between participants, during the timeline captured for each hurricane. A graph showing information outreach and progression over time shows that the intensity of communication on social media peaks for each hurricane shortly before or after it makes landfall. In the case of Maria, a significant amount of conversation continues for more than a week after the hurricane ends. This signifies that there are post-disaster management strategies in place, rescues, and rebuilding efforts that are starting to evolve.

One visualization illustrates the changing degree of social cohesion throughout the timeline of each hurricane. Visualizations of the social media networks over time for each hurricane show how active participants were on specific days – before, during, and after the hurricane. When the data is visualized, it becomes clear that citizens dominated the social media networks during Harvey and Irma, while social media networks for Maria were heavily based on politics and government participants.

The researchers hope their new method for tracking and visualizing social media communications over time and quantifying social cohesion during natural disasters will contribute to future risk management and disaster mitigation policies. “Because we identify the types of actors in a social network and how this network varies daily, decision makers could use this measurement to release strategic communication before, during, and after a disaster strikes – thus providing relevant information to people in need,” says Ramirez-Marquez.

In light of the disastrous impacts of Hurricane Ida on the people of New Orleans, Ramirez-Marquez says, “If we had a national database of the communications pre-during-post disaster then we would be able to better identify the needs of a community and the limitations of current policy and response. It is concerning that, for example, the communities that experienced the harshest effects during Katrina will again be harshly affected during Ida which shows a lack of learning from past events.”


Summarized from Risk Analysis, Social Cohesion: Mitigating Societal Risk in Case Studies of Digital Media in Hurricanes Harvey, Irma, and Maria by Gongora-Svartzman, G (Carnegie Mellon University), and Ramirez-Marquez, JE (Stevens Institute of Technology). Copyright 2021 The Authors. All rights reserved. 

About Heinz College of Information Systems and Public Policy
The Heinz College of Information Systems and Public Policy is home to two internationally recognized graduate-level institutions at Carnegie Mellon University: the School of Information Systems and Management and the School of Public Policy and Management. This unique colocation combined with its expertise in analytics set Heinz College apart in the areas of cybersecurity, health care, the future of work, smart cities, and arts & entertainment. In 2016, INFORMS named Heinz College the #1 academic program for Analytics Education. For more information, please visit