Response to Flash Flood Warnings: State of our Knowledge Burrell E. Montz Department of Geography East Carolina University [email protected]
Jan 11, 2016
Response to Flash Flood Warnings: State of our Knowledge
Burrell E. MontzDepartment of Geography
East Carolina [email protected]
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, http://www.geo.txstate.edu/lovell/IFFL/research.html
Vehicle Deaths
Source: League, 2009, http://www.geo.txstate.edu/lovell/IFFL/research.html
Gender Breakdown*
* Where reported
Source: League, 2009, http://www.geo.txstate.edu/lovell/IFFL/research.html
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 Factors IndicatorsSocio-economic and demographic attributes
Age, gender, income, profession, family situation
Social structures Cohesion of community; social networks
Infrastructure Building quality and types
Attitudinal, psychological, and knowledge factors
Experience, risk perception, views of nature, press coverage
Warning systems Communication 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?
http://blogs.davenportlibrary.com/sc/wp-content/uploads/2008/04/no-wading.jpg