The effects of adaptation measures on hurricane induced property losses: Which FEMA investments have the highest returns?

This paper evaluates the relative effectiveness of FEMA expenditures on hurricane induced property losses. We find that spending on FEMA ex-ante mitigation and planning projects leads to greater reductions in property losses than spending on ex-post adaptation programs – specifically, a one percent increase in annual spending on ex-ante risk reduction and warning projects reduces damages by 0.21 percent while a one percent increase in ex-post recovery and clean-up spending reduces damages by 0.12. Although both types of program spending are effective, we find the marginal return from spending on programs that target long-term mitigation and risk management to be almost twice that of spending on ex-post recovery programs. With the predicted increases in the frequency and severity of North Atlantic hurricanes in the future, our findings suggest there are important potential gains that could be realized from the further diversification of FEMA spending across project categories.     

Public orders and personal opinions: household strategies for hurricane risk assessment

Abstract

This paper examines the relationship between household evacuation decisions and official emergency management practices in light of recent increases in the availability and diversity of hurricane-related information. While we focus on Hurricane Floyd in South Carolina, we incorporate findings of our longitudinal research effort covering the last four years and six post-1995 hurricane threats to the state. While only 64% of residents in the mandatory evacuation zone complied with the Hurricane Floyd evacuation order, over 80% agreed that calling an evacuation was an appropriate precautionary response given the uncertainties of the storm. Longitudinal surveys indicate that Horry County residents have developed a fairly robust strategy in making evacuation decisions. This “hurricane savvy” population depends more heavily on individuals' assessments of risks than on official orders. Individual assessment practices differ from official orders in that greater weight is given to household circumstances and preferences, the diligent monitoring of a variety of information sources, and the incorporation of past experiences into the decision-making process. Surveys indicate differences between the general public and officials in terms of priorities and preferences about hurricane evacuations. The public demands more information about the hurricane threat. Officials place more emphasis on planning evacuation routes and public safety measures.     

Return delays and evacuation order compliance: the case of Hurricane Georges and the Florida Keys

Abstract

Using interview data, we examine the effects of the heavily publicized delays in reentering the Florida Keys after Hurricane Georges on future evacuation intent. Of particular interest is the finding that the delays will have less influence on the future evacuation decisions of those who experienced them than on those who learned of them from secondary sources. Fear of return delays is only one factor in evacuation decision-making, albeit an understudied one. For this sample of evacuees, perceived risk is the most salient factor, and this risk assessment is not sufficiently diminished by the inconveniences, such as delays, associated with evacuation. For non-evacuees, however, the delay factor appeared to only increase their reluctance to evacuate the next time, despite their level of perceived risk.     

Assessing the Effects of Nutrient Management in an Estuary Experiencing Climatic Change: The Neuse River Estuary, North Carolina

Eutrophication is a serious water quality problem in estuaries receiving increasing anthropogenic nutrient loads. Managers undertaking nutrient-reduction strategies aimed at controlling estuarine eutrophication are faced with the challenge that upstream freshwater segments often are phosphorus (P)-limited, whereas more saline downstream segments are nitrogen (N)-limited. Management also must consider climatic (hydrologic) variability, which affects nutrient delivery and processing. The interactive effects of selective nutrient input reductions and climatic perturbations were examined in the Neuse River Estuary (NRE), North Carolina, a shallow estuary with more than a 30-year history of accelerated nutrient loading and water quality decline. The NRE also has experienced a recent increase in Atlantic hurricanes and record flooding, which has affected hydrology and nutrient loadings. The authors examined the water quality consequences of selective nutrient (P but not N) reductions in the 1980s, followed by N reductions in the 1990s and an increase in hurricane frequency since the mid-1990s. Selective P reductions decreased upstream phytoplankton blooms, but increased downstream phytoplankton biomass. Storms modified these trends. In particular, upstream annual N and P concentrations have decreased during the elevated hurricane period. Increased flushing and scouring from storms and flooding appear to have enhanced nutrient retention capabilities of the NRE watershed. From a management perspective, one cannot rely on largely unpredictable changes in storm frequency and intensity to negate anthropogenic nutrient enrichment and eutrophication. To control eutrophication along the hydrologically variable freshwater–marine continuum, N and P reductions should be applied adaptively to reflect point-source–dominated drought and non–point-source–dominated flood conditions.     

Multi-hazard failure assessment of atmospheric storage tanks during hurricanes

Hurricane as one of the most destructive natural hazards can make a devastating impact on the industrial equipment, especially atmospheric storage tanks, leading to the release of stored chemicals and disastrous safety and environmental issues. These catastrophic consequences are caused not only by strong winds but also by the torrential rainfall and inundating floods. The objective of this study is to present a risk-based methodology for assessing and reducing the vulnerability of atmospheric storage tanks to hurricanes. Considering the shell buckling, flotation, sliding, and roof sinking as dominant failure modes of atmospheric storage tanks during hurricanes, Bayesian network (BN) has been employed to combine the failure modes while considering their conditional dependencies. The probability updating feature of the developed BN was employed to indicate that the flood is the most critical hazard during hurricanes while the impact of wind and rainfall cannot be neglected. Extending the developed BN to an influence diagram, the cost-benefit filling of storage tanks with water prior to the advent of hurricanes was shown as a viable measure for reducing the damage probability. The results show that the proposed methodology can be used as an effective decision support tool for assessing and reducing the vulnerability of atmospheric storage tanks to natural hazards.