Tuesday, 24 January 2012: 2:15 PM
Deriving Population Exposure Fatality Rate Estimates for Tornado Outbreaks Using Geographic Information Systems (GIS)
Room 243 (New Orleans Convention Center )
In this proof-of-concept study we looked at several issues regarding the derivation of population exposure to and fatality rate estimates for two widespread tornado outbreaks. The two events studied are the April 3, 1974 and April 27, 2011 tornado outbreaks within the state of Alabama. We used GIS, along with tornado path information and U.S. Census data from 1970 and 2010, to perform an analysis on these outbreaks. We attempted to determine if tornado warnings have become more effective over time at reducing the number of fatalities. Another prime motivation was to determine if it was possible to compare past and present day outbreaks from a population density perspective. We found that the effectiveness of tornado warnings did improve from 1974 to 2011, and we determined that when comparing outbreaks containing multiple tornadoes over wide areas we can have reasonably high confidence in using just county level census data; although higher resolution track level census data would likely be preferable for studying a single tornadic event. We also found that the accuracy of determining fatality rates is directly related to the accuracy of the tornado path data at the tract level. Finally, we believe through this analysis that GIS can be used to innovatively and accurately evaluate tornado warning effectiveness.