Why Some People Choose Not To Evacuate During Wildfires

Light winds and chilly nighttime temperatures are helping firefighters battle what is left of the Thomas fire in Southern California. The blaze which is now the largest wildfire in California history is 89% contain. Thousands of people were under mandatory evacuation orders which were lifted last week. Not everyone who was ordered to leave their homes for their safety obeys those orders. We have a study on what causes some people to stay put in the face of a raging Wildfire. Joining me is Sarah McCaffrey a social science researcher with the U.S. Forest Service. Welcome to the program, Sarah. The Thomas fire, like the wine country fires began by taking people by surprise in the middle of the night. Those people had to rent from their homes which were already on fire. That's the type of situation mandatory evacuations are hoping to avoid, isn't it? >> The mandatory evacuation is really when the fire is approaching and you have time to evacuate more thoughtfully so to speak. That is what it's about. Getting people out of the area before the fire gets to there home. >>> How do authorities decide who should evacuate. How high does the risk have to be that the fire is going to be in that direction. >> It is a joint decision that is made by the sheriff in the incident commander for the fire. They look at a wide range of variables. >>> What has a forest service found out about why some people have not evacuated. >> What I have been doing with my research is trying to understand why there are some people who evacuate and leave early. There are some and a large portion who wait to see conditions. And then there's a small portion who stay to defend their homes. The stay to defend their homes is because in some situation they can improve the chances that their house will survive. The wait and see, they are trying to figure out if the risk is high enough for them to actually make the effort to evacuate. >>> What have you learned about what the factors are that people rely on when they are deciding whether or not they want to leave their homes? >> What we found is that official cues are critical to everyone. And that would be the mandatory evacuation or an official thing that like you should leave. The people who leave early pretty much rely on official cues. What we found is that people who wait and see also rely on physical cues. They are looking at the flames, the smoke, to ascertain how much of a threat the fire is to them. >>> How good are people at reasoning -- reading those physical firesides? >> We don't know. We have not asked that question. I think that's a good question to ask. A lot of people don't understand how fast a fire could travel in the right conditions. >>> I read that you talk to one person who said that I did not want to leave as the sky was still blue. Does that indicate to you that they are misreading some of the signs? >> It is an example of how they may not know how to read a sign. A Blue Sky may be okay or it may not depending upon the topography and the other factors. >>> We heard in Australia that also has to contend with wildfires, they have a policy of a first stay and defend rather than first evacuate. You talked about people staying to defend their homes. First of all, why does Australia handle this differently? >> The Australian policy actually is not first stay and defend, it is a choice. It is basically because they recognize that they cannot force people to evacuate. Most of the state there. and second the recognition is that if your house is well-prepared, you can increase your house a survivor rate. And most people and their experience died while evacuating at the last minute. They would've been better off staying inside of their house which would've protected them from the heat. That is why they focus on those. But they have reached the point to where they recommend everybody leave early. But they also state it as a choice. >>> Is everyone trying that same approach here? >> There are some places that looked into it. There is a fire department in Montana that has for their own reasons adopted it. It is complicated. It is not straightforward to introduce. It is a completely different policy from the one that we practiced for 60 years. >>> What can we learn from watching or evaluating a reporting on who evacuate and who does not from specific fires? >> From the studies that we can tell is what they are making the decisions based on. That can help us think better about what type of information might help improve outcomes in future fires. >>> Are these the same kind of factors that go into whether people evacuate from other types of natural disasters like hurricanes? >> We found that a lot of the factors we found in hurricane studies apply to wildfires. There are somewhat unique things to wildfires in terms of the studies with hurricanes. They are a bit more predictable. You have a lot more warning when a hurricane will show up. With wildfires, they are more unpredictable because of weather and wind changes. You may not have any warning such as what happened in Napa and the Thomas fire. And what may make sense at one moment in time may not make sense five minutes later because of the changes in the weather pattern. It makes the decision process more complicated. >>> I have been speaking with Sarah McCaffrey a science researcher with the U.S. Forest Service. Sarah, thank you. >> Thank you very much, my pleasure.