COLUMBUS, Ga. (WRBL) – Nearly nine months after tornadoes devastated the community of Beauregard, Ala., a team of Auburn professors study the circumstances that led to the destruction on March 3, and the loss of 23 lives.
One of those professors, David Roueche, Ph.D. presented some of the team’s preliminary findings to a Columbus State University meteorology class taught by Scott Gunter, Ph.D.
The presentation was called “The Makings of Disaster: How Hazard, Exposure, and Vulnerability Intersected in the March 3rd, 2019 Beauregard, AL Tornado.” The study focuses on the multitude of factors that came together on that fateful day and classifies them into three “ingredients for disaster,” according to Roueche.
Roueche says that the three ingredients of a disaster are Hazard, Exposure, and Vulnerability, which equal to what he calls Disaster Risk.
“In many cases, you can’t do anything about the hazard,” Roueche said, “We only have control over vulnerability.”
To understand Roueche’s study, the three unique aspects that make up disaster risk must be defined:
- Hazard: The tornado
- Exposure: Property, people, and items that could be affected by the hazard.
- Vulnerability: Factors that lead to different amounts of damage.
According to the study, the vulnerability factors that can be controlled are mainly focused on preparedness and construction. This includes the types of homes built, and the nearness of shelter locations.
Roueche says that much of the damage from the March 3 tornadoes came as a result of multiple construction-based issues. The factors with the most impact on the damage are tied to what Roueche said is physical vulnerability, especially in mobile homes.
Not only is the housing density in tornado-vulnerable areas higher in the South, like in Alabama, but the amount of homes that are affected by severe and extreme weather are typically older houses, and prefabricated or mobile homes.
Of the 23 fatalities from the March 3rd tornadoes, 19 of the victims were in mobile or prefabricated homes, with the other four located in what Roueche referred to as permanent home locations. The majority of the structures damaged in the storm were also single-family homes.
The type of homes where the victims were lost is of particular importance due to their built-in safety factors and overall structural integrity.
Roueche and his team found in their initial surveys that the bulk of the homes were in various states of disrepair, especially the anchors that held the homes in the ground. The study noted a widespread factor that affected the homes was corroded anchors, as well as material degradation.
This means structures’ resistance was lowered by a lack of long-term maintenance on the different houses.
“What we’re trying to look at—-and this is still early, the event just happened but—-are there ways that we can slow the progression of the failure down? What we’re seeing is a lot of what we in engineering call brittle failures, meaning that the whole structure picks up and gets thrown, instead of what we want to see, which is a progressive failure…the roof starts to come off, a little bit more of it comes off, and the the walls start to collapse, so it’s a slow progression of damage. Where we saw the fatalities happening in this event was when entire homes were getting picked up and thrown.”Dr. David Roueche, Assistant Professor of Civil Engineering at Auburn University
All of these factors contributed to the primary damage that affected the community coming from wind speeds during the storm, rather than debris.
Geography also factored into the vulnerability of the homes in the path of the tornadoes on March 3rd, Roueche said.
In the United States, mobile homes make up six percent of available housing, according to studies by the U.S. Census Bureau. In comparison, Roueche says that 54 percent of the housing-related tornado deaths are from victims in manufactured or mobile homes.
While the study is still in progress, the results that were presented are available now for public view, at StEER.network, where Roueche and his colleagues are publishing their findings as they come.