The Influence of Previous Disaster Experience and Sociodemographics on Protective Behaviors during Two Successive Tornado Events

Authors: Amber Silver and Jean Andrey

Discipline: Geography

Hazard of Interest: Tornado

Methods: Semi-structured interviews and close-ended questionnaires

Key Research Issues:

• This research examines two successive, potentially tornadic events that occurred in Goderich, Ontario, Canada on 21 August 2011 and 24 August 2011.
• The purpose of this socio-behavioral study was to investigate the influence of previous disaster experience on risk perception and response to a low-probability, high-impact disaster.

Key Research Findings:

• Physical cues were the primary motivators of protective action on 21 August 2011, while the Environment Canada tornado warning was the primary motivator on 24 August 2011.
• Respondents were more likely to take protective action during the subsequent storm on 24 August 2011, regardless of whether they were physically present for the tornado on 21 August 2011. This highlights the important influence of indirect disaster experience on hazard perception and response.
• Socio-demographics were not found to influence protective decisions made on 21 August 2011, while gender (female) was related to decision-making on 24 August 2011.
• The intense media coverage of the impacts of the 21 August 2011 tornado may have contributed to a social amplification of risk on 24 August 2011.

Tornado Warning Trade-Offs: Evaluating Choices for Visually Communicating Risk

Authors: Kevin D. Ash et al.

Discipline: Geography

Hazard of Interest: Tornado

Methods: Questionnaire, Mann-Whitney U test, Getis-Ord G*i Hotspot analysis, linear-by-linear chi-square test, GIS

Key Research Issues: Do deterministic-style and probabilistic-style tornado warning graphics elicit different fear responses and protective action intentions?

Key Findings:

• The deterministic warning showed higher fear and protective action responses than the probabilistic-style warnings

• Participant responses dropped off more sharply near the edge of the deterministic warning

• Probabilistic warnings elicited clusters of high fear and protective action responses coincident with the higher probabilities of a tornado, which aided in understanding the direction of movement implied by the warning shape and color patterns

• The cluster of high responses for the deterministic warning was near its centroid and did not clearly indicate that viewers understood the direction of movement from the shape alone

Performance Assessment of a Heat Wave Vulnerability Index for Greater London, United Kingdom

Authors: Tanja Wolf et al.

Discipline: Geography

Hazard of Interest: Heat

Methods: Principal component analysis, Mapping, Poisson regression analysis, Independent samples test, Skill scores

Key Research Issues: Performance Assessment of a multivariate heat wave vulnerability index (HVI) developed for London, United Kingdom. The HVI is assessed in terms of its ability to predict whether mortality and ambulance callout attain above average levels during heat wave events.

Key Findings: The assessment results reveal that the HVI as well as a simple single variable index that represents age as a heat risk factor (the elderly index) offer potential as a priori indicators of the level of ambulance callout and mortality for all summer days and heat wave events, respectively.

Weather, Climate, and the Economy: Explaining Risk Perceptions of Global Warming, 2001–10

Authors: Wanyun Shao et al.

Discipline: Geography

Hazard of Interest: Risk perceptions of Global Warming

Methods: Ordered-logit regression with clustered standard errors, GIS

Key Research Issues: Weather, climate, or economy – what explains the variations in risk perceptions of global warming in the first decade of 21st century?

Key Findings:

1. Summer temperature trends over the past 10 years, among other weather and climate  measures, are shown to have consistently positive effects on public perceptions of global warming.
2. Macroeconomic conditions—represented by the unemployment rate at the county level—do not appear to influence public perceptions of global warming.
3. Democrats and liberals are more likely than Republicans and conservatives to see global warming as an immediate and serious problem.
4. Young people, women, racial minorities, and individuals with lower income and higher levels  of education tend to be more concerned about the impacts and severity of global warming than their counterparts.

Somali Piracy and the Monsoon

Authors: Duncan Cook and Sally Garrett

Discipline: Geography, Environmental Science

Hazard of Interest: Pirates

Methods: Remote sensing, mapping

Key Research Issues: Somali-based pirates operate across a vast ocean area that includes some of the busiest shipping lanes on the planet. This research set out to characterize the wind and wave conditions that existed during pirate attacks in recent years.

Key Findings: In 2011-2012, pirate attacks in the Indian Ocean region mainly occurred in the early and later half of the year, with very few attacks launched during the summer monsoon period. We propose that the rough seas and strong surface winds of the summer monsoon (JJA) have prevented piracy for periods of up to three months during 2011-2012. Remote sensed and surface weather data suggest clear environmental thresholds exist that have prevented pirates launching successful attacks. Once wind speeds exceeded 9 m/s and waves of sea state 4 (wave heights above 2.5 m) were recorded, open-water maritime piracy was halted. In contrast, the lower wind speeds and wave heights during the winter monsoon, premonsoon [March–May (MAM)], and postmonsoon [September–November (SON)] seasons were not a deterrent for pirates operating in the Indian Ocean region.