Response to Flash Flood Warnings: State of our Knowledge Burrell E. Montz Department of Geography East Carolina University

Topics Short fuse events – Flash floods – Tornadoes Overview of studies Summary of findings So what...?

There remains, then, the need for a mathematical model of human response to warnings, a model that would mimic all essential characteristics of human response in a setting of a local flood warning system and that would enable one to predict the outcomes of decision- event pairs. Krzysztofowicz, R., 1993 The Problem Reality

Components of Public Response Hear Understand Believe Personalize Decide to act Respond

What People Say Gruntfest et al., 2008

What People Do League, 2008

Actual versus Anticipated Behavior Difference between what people say and what they do Importance of context and circumstance Difficult to document impacts of – Time – Memory – Cognitive dissonance

Tornado Studies: Sources of Information Schmidlin et al., 2009; Schmidlin and King, 1997; Balluz et al., 2000

Actions and Reasons: 35% took shelter Positive actions correlated with – Perceived danger – Presence of children – High school education – Hearing warning – Having a basement – Being married Negative actions correlated with – Previous damage – Less education – God’s will – Lack of access to shelter – Limited mobility No correlation – Age, gender, race – Lead time – Owning NWR – Family size – Previous experience

NWS Service Assessments Super Tuesday 2008 Tornadoes – 57 dead – 18 (32%) heard some warnings – 11 (61%) heeded warnings – 8 (44%) sought shelter – 6 (33%) did not Mothers’ Day 2008 Tornadoes – 21 dead – 11 (52%) knew of warning – 10 (47.6%) tried to take shelter ________________________ – 14 groups interviewed – 6 (42.8%) heard official warning – 6 heard from family or friends – 4 (28.5%) sought shelter – 6 tried but it “came too fast”

Flood Fatalities Source: League, 2009,

Vehicle Deaths Source: League, 2009,

Gender Breakdown * * Where reported Source: League, 2009,

So what about warnings?

But... League, 2009 There is a difference between Intentional Drivers Situational Drivers

False Alarms, Near Misses, and Response What we know – Very different definitions of false alarms NWS vs public – Perceptions of accuracy vary NWS vs public – Cry wolf or warning fatigue or neither – Influence of event type – We don’t know enough Barnes et al., 2007

And... There is no ONE public Different languages Different understandings Different situations Different capabilities Different needs Vulnerability FactorsIndicators Socio-economic and demographic attributes Age, gender, income, profession, family situation Social structuresCohesion of community; social networks InfrastructureBuilding quality and types Attitudinal, psychological, and knowledge factors Experience, risk perception, views of nature, press coverage Warning systemsCommunication channels and relevancy Public policy/risk management System of actors; decision-making process Spatial and temporal aspects of event Time of day; location; local knowledge

Long way to go...

NWS mission: Protect life and property NWS warnings are only the beginning of meeting this mission Warnings move through various paths to the public Warnings are received and understood differently Collaborative effort required to get positive, protective responses Social science research required to understand why people respond the way they do under what circumstances Conclusion

Thank you Any questions you’d like to wade through?