Graduation Year


Document Type




Degree Granting Department


Major Professor

Graham A. Tobin, Ph.D.


Flood hazards, Hazard perception, Risk communication, Flood policy, National flood insurance program


Loss prevention and distribution must begin well before a flood event at multiple levels. However, the benchmarks and terminology we use to manage and communicate flood risk may be working against this goal. U.S. flood policy is based upon a flood with a one percent chance of occurring in any year. Commonly called the "hundred year flood," it has been upheld as a policy criterion, but many have questioned the effectiveness of hundred year flood terminology in public communication. This research examined public perceptions of the hundred year flood and evaluated the comparative effectiveness of this term and two other methods used to frame the benchmark flood: a flood with a one percent chance of occurring in any year and a flood with a 26 percent chance of occurring in thirty years.

This research also explored how flooding and flood risk messages fit into the larger context of people's lives by modeling the relationships between flood related understanding, attitude and behavior and the situational and cognitive contexts in which these factors are embedded. The final goal was to come up with locally based suggestions for improving flood risk communication. Data were collected in the Towns of Union and Vestal, New York. Participants were adult residents of single family homes living in one of two FEMA designated floodplains. Face to face surveys and focus groups were used to gather information on respondents' flood experience and loss mitigation activities; general perception of flood risk and cause; flood information infrastructure; perceptions associated with specific flood risk descriptions; and basic demographic data. Focus groups were also asked to suggest improvements to flood risk communication.

Results indicated that experience was the most influential factor in perception and behavior. Additionally, there was little evidence that understanding led to "appropriate" behavior. The 26 percent chance description was the most effective when both understanding and persuasion were included, but interpretations of probabilistic flood risk messages were highly individualized. Finally, regulatory practice likely influences attitude and behavior and may emphasize the likelihood of a particular flood at the expense of the possibility of flooding in general.