Engineering-Based Hurricane Risk Estimates and Comparison to Perceived Risks in Storm-Prone Areas

Shadow evacuees have negative effects on hurricane-induced evacuation operations. The goal of this study is to understand and explain shadow evacuation by comparing perceived risks with engineering risk estimates at the household level--particularly in nonevacuation zones where undesirable evacuation decisions are made--rather than by comparing perceived risks with regional hazards that previous studies have measured. A proposed methodology to compute engineering risk estimates from hurricane hazards is illustrated for approximately one million properties in Harris County, Texas. These risks are then compared with risk perceptions from a survey of residents which was conducted after Hurricane Ike's landfall in 2008. The results show that evacuation behavior is related to a hurricane-induced surge and wind risk mismatch and that risk overestimation and underestimation are more likely seen in locations near the waterways. The results also show that shadow evacuation is partly attributable to risk overestimation. The overestimation of damage risk from wind or surge correlates to 108,031 shadow evacuees. This is more than the total number of households in Galveston County that need to evacuate in the event of a hurricane--primarily through Harris County--and who may be subjected to traffic delays caused by shadow evacuees. The spatial distribution of risk mismatch provides opportunity for emergency managers to effectively plan and respond to hurricanes, while preventing unwanted evacuation.

[1]  Michael Todinov,et al.  Risk-Based Reliability Analysis and Generic Principles for Risk Reduction , 2006 .

[2]  C. V. Anderson,et al.  The Federal Emergency Management Agency (FEMA) , 2002 .

[3]  R. Morss,et al.  An In-Person Survey Investigating Public Perceptions of and Responses to Hurricane Rita Forecasts along the Texas Coast , 2007 .

[4]  Bruce R. Ellingwood,et al.  Performance-Based Engineering of Wood Frame Housing: Fragility Analysis Methodology , 2002 .

[5]  Bob Edwards,et al.  Gender and Evacuation: A Closer Look at Why Women are More Likely to Evacuate for Hurricanes , 2002 .

[6]  Ernest J. Henley,et al.  Reliability engineering and risk assessment , 1981 .

[7]  Devika Subramanian,et al.  Performance assessment of topologically diverse power systems subjected to hurricane events , 2010, Reliab. Eng. Syst. Saf..

[8]  Nicole Dash,et al.  Evacuation Decision Making and Behavioral Responses: Individual and Household , 2007 .

[9]  Rachel A. Davidson,et al.  Forecasting Changes in the Hurricane Wind Vulnerability of a Regional Inventory of Wood-Frame Houses , 2007 .

[10]  David V. Rosowsky,et al.  Long-term hurricane risk assessment and expected damage to residential structures , 2001, Reliab. Eng. Syst. Saf..

[11]  Bruce R. Ellingwood,et al.  Hurricane damage to residential construction in the US: Importance of uncertainty modeling in risk assessment , 2006 .

[12]  Michael K. Lindell,et al.  Risk Area Accuracy and Evacuation from Hurricane Bret , 2004 .

[13]  Walter Gillis Peacock,et al.  Social Science Research Needs for the Hurricane Forecast and Warning System , 2007 .

[14]  Jerry T. Mitchell,et al.  Revealing the Vulnerability of People and Places: A Case Study of Georgetown County, South Carolina , 2000 .

[15]  Ioannis K. Tsanis,et al.  Developing Geographic Information Systems for Land Use Impact Assessment in Flooding Conditions , 1998 .

[16]  S. Brody,et al.  Hurricane risk perceptions among Florida's single family homeowners , 2005 .

[17]  Kevin Huang,et al.  HAZUS-MH Hurricane Model Methodology. I: Hurricane Hazard, Terrain, and Wind Load Modeling , 2006 .

[18]  Kyung Ho Lee,et al.  Fragility assessment for roof sheathing failure in high wind regions , 2005 .

[19]  Bob Edwards,et al.  Heading for higher ground: factors affecting real and hypothetical hurricane evacuation behavior , 2000 .

[20]  Gary W. Brunner,et al.  HEC-RAS (River Analysis System) , 1996 .

[21]  Lawrence A. Twisdale,et al.  SIMULATION OF HURRICANE RISK IN THE U.S. USING EMPIRICAL TRACK MODEL , 2000 .

[22]  Jayajit Chakraborty,et al.  Population Evacuation: Assessing Spatial Variability in Geophysical Risk and Social Vulnerability to Natural Hazards , 2005 .

[23]  Devika Subramanian,et al.  Who evacuates when hurricanes approach? The role of risk, information, and location. , 2010, Social science quarterly.