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Eve Gruntfest ecg@uccs.edu Kansas City January 22, 2009. Lessons from the Warning Project. The Big Thompson Flood in Colorado July 31, 1976. 140 lives lost – 35 miles from Boulder Studied the behaviors that night Who lived? Who died? Led to detection & response systems.
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Eve Gruntfest ecg@uccs.edu Kansas City January 22, 2009 Lessons from the Warning Project
The Big Thompson Flood in Colorado July 31, 1976 • 140 lives lost – 35 miles from Boulder • Studied the behaviors that night • Who lived? • Who died? • Led to detection & response systems Focus on flash floods & warning systems
Our 2003-2008 National Science Foundation project aimed to • Evaluate impacts of • Demographic change • New & different sources of information • Test conventional wisdom about • False alarms/ close calls Evaluate previous trauma experience & warning perceptions
What we know about warnings – Public response components • Hear/receive • Understand • Believe • Personalize • Decide to act • Respond Reinforcing what Havidan said this morning: The warning process is complex
Why Austin & Denver Similarities Large Growing cities Diverse populations Vulnerable to flash flooding
Warning project methodology • Survey Development • 1 year • Input from officials & hazards researchers • Survey format • Likert scale & true/false • Demographic questions • Experience with flash floods & trauma • Surveys in English & Spanish to selected respondents • Survey is available – for follow up studies
Mail survey • 6000 surveys sent to residents in or near the floodplain • 1017 surveys returned
Where do people get their weather information? • Best way for officials to warn you about a flash flood?
A flash flood warning indicates a more serious threat than a flash flood watch 92% 8% n=1031
I take flash flood warnings seriously 92% 8% n=1017
The best way for officials to warn you about a flash flood? N=1020
Is overwarning a problem: False alarm issues --”cry wolf” may not be a major problem • People prefer more warnings even if there are more false alarms • No measurement of “close calls” & “near misses” • Events occur but not exactly in the warning areas or with exactly the predicted intensity • How about new categories? New metrics?
Officials are too sensitive to the possibility of flash flooding N = 1031
Realizing it’s difficult to predict flash floods, I prefer more warnings even if there are more false alarms or close calls N= 1047
Austin by GenderRealizing it’s difficult to predict flash floods, I prefer more warnings even if there are more false alarms or close calls X² =4.150, p <.05
Extreme speed of watershed responses Extremely short lead-time for warnings New ways of representing what we know – include hydrology - Isabelle Ruin new time/space analysis
Challenging our assumptions - For flash floods – shorter lead time may be better than longer lead time • Smaller area under warning • Is there a best leadtime? • Concerns with “too much leadtime?” • Are these warranted?
We need new metrics –Socially relevant verification Forecast verification is difficult in rural areas
Since not all meteorological hazards are created equally ---What are acceptable levels of risk? Infrastructure is aging! (levees for category 2,3,4,5?) --- How do we measure warning success? If 20 people die in Greensburg, KS – warnings can still have saved hundreds
I would drive through an intersection with six inches of water running across it 63% say they would NOT DRIVE through it Is this good or bad news?
Tailor message for local hazards --Maricopa County (Phoenix, AZ) • Floodwaters can conceal a damaged roadway • Flash Floods rarely last more than an hour • Don’t trade an hour for a lifetime
Challenge of confronting ads from car companies Ad says: Warning: use the cup holders at your own risk How to convince people they are better Wet than Dead?
Behavioral survey project Observe driver’s behavior at low water crossings in Texas • http://70.253.207.10/view/index.shtml • Quantitative survey • Use of video • car counting • Qualitative survey • Use Youtube video, travels log & in-depth interviews
WHAT WERE THEY THINKING? USING TO OBSERVE DRIVER BEHAVIOR CROSSING FLOODED ROADS 2009 Geography Master’s thesis by Cedar League
INTENTIONAL/SITUATIONAL • Intentional drivers:purpose was to film the flood water, or to drive in the flood water (for fun). 59% (n=31) • Situational drivers: purpose of trip was based upon their current situation, like driving to or returning from work. 41% (n=21)
Are warnings always possible? Do they always make THE difference? Sirens – Technical capability for smaller than county warning – But whole county hears sirens?
West Nile Virus study epidemiology- awareness example • Folks >50 years old most vulnerable to severe manifestations • Campaign for elderly Nobody identifies themselves as “elderly”
How do we address nuisance events vs catastrophic events? Height of the 1997 Fort Collins flash flood
Warning project findings • Weather information requirements of each user community are highly specialized • The weather research community has not focused on the individual needs of specific user communities • Existing social science studies barely scratch the surface – more comprehensive studies must be done to have more confidence in policy change based on findings
In 2018 – yet another decade from now…When we meet – we must see Easy natural collaborations between physical scientists, planners, engineers, broadcasters, emergency managers, social scientists & others Fewer deaths & reduced losses from weather events & a better understanding of how people use weather information
Warning project publications Environmental Hazards 2007 -- Vol 7 • C. Benight, E. Gruntfest, M. Hayden, L. Barnes Trauma and short-fuse weather warning perceptions • S. Drobot C. Benight, E. Gruntfest Risk factors for driving into flooded roads • M. Hayden, S. Drobot, S. Radil, C. Benight, E. Gruntfest, L. Barnes Information sources for flash flood warnings in Denver, CO and Austin, TX • I.Ruin, J-C. Gaillard, C. Lutoff How to get there? Assessing motorists’ flash flood risk perception on daily itineraries