Evaluating tornado casualty rates in the United States

Abstract

Tornadoes account for nearly one fifth of all natural hazard fatalities in the United States, yet there exist no general estimates of casualty rates across the country. Here tornado casualty rates are estimated for all casualty-producing tornadoes over the period 1995-2016 using tornado level information related to the population and total housing units within each damage path. The 22-year United States per-capita casualty rate is 2.3%, while the 22-year United States per-housing unit casualty rate is 5.4%. Injury and fatality rates are also estimated over the same period. The 22-year United States per-capita fatality rate is .15% and the per-capita injury rate is 2.1%. The per-housing unit fatality rate is .36% and the per-housing unit injury rate is 5.1%. Casualty rates are further examined through subsets of Enhanced Fujita rating, state boundaries, and county boundaries. When used in conjunction with estimates of future changes in tornado behavior and population growth, these casualty rates can help predict tornado casualty events in communities throughout the United States.

Tornado fatalities in context: 1995--2018

“…The 24-year per-capita fatality rate is .32% and the per-housing unit fatality rate is .75%. Perhaps unsurprisingly, when considering only killer tornadoes, the fatality rate is higher at both the percapita and per-housing unit level relative to casualty-producing tornadoes (Fricker 2020a). This is likely due to a combination of smaller numbers and more intense tornadoes (i.e.…”

“…Population and housing data are evaluated at the Census tract level so as to be large enough to include the entire region of interest and small enough to provide more detailed information than other available geographies (e.g. state-and county-level) (Fricker 2020a). Here, data from the 1990 and 2000 Census, as well as the 2010 ACS five-year estimates are included.…”

“…In response, here we build on the work of Fricker (2020a) to estimate tornado fatality rates in killer tornadoes-those that produce at least one death-within the contiguous United States over the period 1995-2018. More specifically, we expand previous estimates of tornado fatality rates along multiple physical and social factors-including fatality location, demographic profiles, and year, month, and hour of occurrence-existing within a spatiotemporal context.…”

A Place-Based Analysis of Tornado Activity and Casualties in Shreveport, Louisiana

“…Shreveport-and more broadly the Ark-La-Tex region-is an area identified as highly vulnerable and susceptible to large tornado casualty events in recent research (Fricker and Elsner, 2019;Fricker, 2020). Tornadoes impacting the city are 2.2 times as long, 1.5 times as wide, and 2.6 times as powerful as the national average, which is likely a driving force behind a per-tornado casualty rate that is well above the national average under any definition-whether all tornadoes or only casualty-producing tornadoes-of the tornado casualty rate.…”

Tornado Fatalities in Context: 1995–2018

“…Knowing the rate at which people are killed in tornadoes at the per-capita or per-housing unit level allows emergency managers, meteorologists, or planners to think about worst-case or what-if scenarios (Clarke 2005;Wurman et al 2007;Antonescu et al 2018) in their local communities. For example, using the fatality rates found in Fricker (2020a), if an emergency manager works for a city of 50,000 people with 10,000 housing units and predicts the worst case scenario for any individual tornado is the impact of half the population and a third of the housing units, they would estimate, on average, that the tornado would result in 38 fatalities (25,000 ×…”