How 'Perceived Vulnerability' Contributes To Whether People Evacuate Before A Hurricane

Sep 4, 2019

For many people, preparing for a hurricane often means making a decision about whether to evacuate or stay and ride out the storm.

This week, in the face of Hurricane Dorian, several counties on Florida’s east coast issued mandatory evacuations, but research shows how people perceive the forecast plays a role in whether they decide to listen to those calls to leave.

Retired Florida State University professor Jay Baker studied this and spoke with WLRN’s Alexander Gonzalez.

WLRN: What made you interested in researching human behavior during hurricane evacuations? What got you into that?

BAKER: I grew up in Louisiana and my first memory of a hurricane was Hurricane Audrey, which occurred there in 1957. I recall stories of people climbing onto the roofs of their houses to get away from the storm surge flooding and there being poisonous snakes, water moccasins on the roofs of their houses. I've been fascinated by hurricanes ever since then.

And I remember being in graduate school and being exposed to the concept of hazard perception. The issue was: why do people live in dangerous places to begin with? Then that kind of evolved into why people take risks in terms of staying and not evacuating. Or is it just a matter of ignorance and not knowing the risk? Or is it a matter of just simply be willing to take the risk?

What are some of the factors that influence how many people actually decide to leave their homes before a storm approaches?

The most important factors are where people live. The beachfront people are much more likely to leave than people farther inland – which is good. People who live in mobile homes are more likely to leave [as well].

A big thing that's kind of hard for the emergency management folks to know is that people perceive vulnerability. That is whether or not they think it would be safe to stay in their home when a storm hits. The vast majority of people, even low-income people, the main reason they give for not leaving, is that they didn't think that they needed to. So that could either be because they thought their house was well built or in a safe location. Or the strong storm wasn't going to be as strong as it might have turned out to be. Or they thought it was going to miss them completely.

We do know that the vast majority of people do not know their evacuation zone. If you call someone in advance and say 'what zone do you live in,' most people can't tell you.

How does intensity play into this perceived vulnerability?

The actual strength of the storm is a big predictor, too. You get more people leaving with a Category 4 or 5 than you do in a 1 or 2. And that's partly because people realize that it poses a greater threat, but it's also because public officials are more aggressive about telling people to leave in those stronger storms.

What can you tell us about the response for Hurricane Dorian?

One of the interesting things that they did more than I've seen in a lot of other storms is a place would say we're going to have a voluntary evacuation now but it's going to become mandatory tomorrow morning at 8 o’clock. I think the motivation behind that is to get people to start preparing to leave. It also gives [emergency management officials] the latitude of canceling it or postponing it, if it turns out that the storm slows down or weakens or changes track.

Given that we may be seeing a future with a lot more flooding, especially in the coastal areas, what do you think about people continuing to stay in those areas where evacuations could become even more frequent?

I have thought about it and I'm not sure that it's going to make a big difference to a lot of people. Some of the places that have the greatest frequency of hurricanes and the greatest vulnerability are places where the population is growing the most and has been growing the most. A lot of it is in South Florida on both coasts.

If it's going to change the likelihood of people living in certain areas, it's probably going to be because people are going to have to start paying more for insurance. Flood insurance, for example, if they ever do away with the federal subsidies, so that we actually have to pay actuarially sound rates for it, and the risk increases as a result of climate change, I think that's going to be a bigger deterrent to people continuing to live in some of the most dangerous areas.

This interview has been edited for length and clarity.