As floods become more frequent, severe, and widespread, getting people to respond appropriately to flood warnings is more important than ever. New research from the University of Vermont shows that the way flood hazard information is presented can dramatically affect not only whether people make the right decision, but also how quickly they make it. The findings are published in the journal Crisis and Risk Communication .
The study addresses a critical gap in flood hazard communication research. Most previous studies have focused primarily on whether warning messages are understandable. However, during an emergency, understanding alone is not enough. People must also process information and take protective action quickly, especially when a delay can make a life-or-death difference. This research is among the first to systematically examine both response accuracy and response speed as equally important measures of communication effectiveness.
"Effective crisis and risk communication is not just about whether people eventually understand a message," said Scott C. Merrill, the study's corresponding author. "It's about whether they can understand it quickly enough to make the right decision when facing a rapidly developing natural disaster."
To investigate how people respond to different flood warning messages, Merrill and his research team developed an interactive serious game that simulated an approaching storm and flooding conditions. Participants received flood hazard messages through virtual mobile-phone alerts and had to choose whether to evacuate or to prepare at home. The study analyzed responses from 746 participants and measured both the speed and safety of their decisions.
Their findings were striking. Warning messages that included Flood Inundation Maps (FIMs) consistently produced the best outcomes, generating both faster and more accurate decisions than traditional text warnings and commonly used infographic formats. Participants responded most effectively to messages that visually showed where flooding was expected to occur, allowing them to rapidly connect hazard information to their own location.
Researchers found that participants receiving flood inundation map messages made decisions in an average of 6.69 seconds and achieved a response accuracy rate of 77.8%. By comparison, participants shown a commonly used flood warning infographic responded more slowly, averaging 8.58 seconds, and responded appropriately to the risk in their circumstances only 57.7% of the time.
The study also highlights the value of innovative research methods for improving public safety. Using a serious game methodology allowed investigators to create realistic decision-making conditions, including time pressure and financial incentives, enabling them to capture behavioral data that would be difficult or impossible to obtain during real flood emergencies. Because participants' rewards depended on responding both rapidly and correctly, researchers were able to measure decisions driven partially by the participants’ instinctive reactions rather than relying on data collected in calm conditions such as by surveys or self-reported intentions.
This behavioral approach offers a powerful new way to evaluate hazard communications before disasters occur, helping emergency managers, communicators, and forecasters identify which messages are most likely to protect lives and property.
The findings arrive at a critical moment as new flood forecasting and mapping technologies are being deployed across the United States. According to the researchers, improving the design of flood-warning messages could significantly increase the public's ability to make timely and appropriate self-protective decisions during emergencies.
"Flood risk communication is often evaluated based on comprehension alone." said Merrill. "Our findings show that speed matters too. A message that people understand but take too long to process may not be effective during a crisis. By measuring both accuracy and response time, we can better understand what truly works when people are faced with urgent, high-stakes decisions."
The researchers conclude that effective flood hazard communication must be evaluated as a behavioral outcome, not simply a communications outcome. By focusing on how quickly and accurately people translate warnings into action, future research can help build more effective early warning systems and improve community resilience amid our era of increasing flood risk.
Computational simulation/modeling
People
"Embedding Flood Inundation Maps in Flood Hazard Communications Improves Response Time and Accuracy: Results from a Serious Game Experiment," is published in Crisis and Risk Communication.
6-Nov-2026
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