When Floods and Coronavirus Collide: Dealing With a Disaster During a Pandemic

Published Apr 14, 2020

Dr. Kristy Dahl reviews NOAA spring flooding and maps the potential collision with COVID-19.

In this episode
  • We continue our coverage of the coronavirus and take a look at how it can collide with other disasters
  • Kristy talks about the increased danger it adds to flooding events and its implications
  • Colleen continues to refine her home recording setup
Timing and cues

Opener (0:00-0:58)
Intro (0:58-2:59)
Interview part 1(2:59-15:02)
Break (15:02-17:00)
Interview part 2 (17:00-26:48)
Outro (26:48-28:27)

Related content
Show credits

Editing: Omari Spears and Brian Middleton
Music: Brian Middleton
Research and writing: Jiayu Liang and Pamela Worth
Executive producer: Rich Hayes
Host: Colleen MacDonald

Full transcript

Colleen: Kristy, welcome to the podcast.

Kristy: Thanks so much for having me, Colleen.

Colleen: So I'll just give you a little warning here since I'm recording from home now and my dog is right behind me and she's sleeping and hopefully her snoring won't come through on the recording and hopefully she won't wake up and start barking, but if she does, we'll maybe pause for a second.

Kristy: No problem. I closed myself into a bedroom, but if my dog starts scratching at the door, we'll have to do the same.

Colleen: Great. So, Kristy, you study the impacts of climate change, severe weather, wildfires, flooding, and extreme heat. Can you tell me about your recent analysis on spring flooding and how that will potentially collide with the coronavirus pandemic?

Kristy: Sure. So as a climate scientist, I'm always looking at the seasonal forecasts that NOAA puts out every season. So every spring, they issue an outlook for the spring season and what it's going to look like in terms of flooding. Spring tends to be a season when we see a lot of heavy rain and flooding. Similarly, they put out forecasts at the start of hurricane season for how many hurricanes we might see. And the other agencies put out forecasts for things like the wildfire season. But, of course, right now, all of our minds, including those of scientists like myself are on the coronavirus and what is happening around our country and around the world. So when NOAA put out its spring flood forecast a couple of weeks ago, my colleague Juan Declet-Barreto and I instantly started thinking about what that flooding could mean for our ability to respond to the coronavirus and how the coronavirus could make it harder for us to respond to flooding if it happens.

So we wanted to look at the intersection of those two things, where are we expecting flooding this spring and where are infection rates expected to be highest in terms of coronavirus. And luckily, we were able to track down data from some epidemiologists at Columbia University, looking at how the infection rate would change over the next few months. So we were able to combine those two datasets and paint a picture of where these two threats really intersect.

Colleen: What does spring flooding usually look like and who's most impacted?

Kristy: So we've seen a trend in the last few years toward more extreme flooding. And that's happening because climate change is increasing the amount of rain that's happening in the heaviest downpours. So essentially, our extreme rainfall events are getting more extreme. And last year was a really good example of that. So last year, we saw really widespread flooding across the whole Midwest from the Dakotas all the way down the Mississippi River. We saw levees being breached and breaking down. We saw heavy losses from the agricultural sector because farmers weren't able to plant their crops or their crops were destroyed by flooding. So we tend to see a lot of this flooding in the Midwest and it tends to affect farmers, but it also affects all sorts of people in vulnerable groups. So you can imagine that if you are already struggling with poverty, having your house flood is just one more really difficult challenge to cope with. So it's definitely a widespread problem and one that seems to be getting worse year by year.

Colleen: So in terms of managing that, how does NOAA define the different levels of severity and what are some of the management practices?

Kristy: So NOAA defines flooding in terms of three different categories. There's minor flooding, moderate flooding, and major flooding. Minor flooding is a type of flooding that doesn't typically affect life or property. So, you know, if you live along the coast, sometimes this is called nuisance flooding or sunny day flooding. You might see a little bit of flooding on roads, maybe in your yard, but it's not really posing a threat to people's lives or their homes. That said, that type of flooding can be disruptive. If the roads surrounding a hospital, for example, become flooded, then, obviously, you could have a disruption of your ability to get to those healthcare facilities. Moderate flooding is a step up from that. So it can pose threats to life and property and it can sometimes require people to evacuate their homes. Major flooding, a good example of major flooding would be something like we saw during Hurricane Harvey in Texas where you have broad swaths of community flooding often accompanied by loss of life, many people needing to evacuate to drier ground.

Colleen: So with spring flooding, how are those predictions made?

Kristy: To predict spring flooding, NOAA takes into account what's happening all over the globe in terms of large-scale climate processes. So things like the position of the jet stream can affect where we see flooding in the country, if there is an El Nino event, that's going to affect where we might see flooding in the country. So NOAA's looking at what's happening from pole to pole around the world and using that to try to get a sense of where we might see flooding and extreme precipitation in the spring.

Colleen: And how accurate are those predictions?

Kristy: The accuracy of those predictions varies from year to year. And, you know, some years, they are pretty well spot-on, other years, not so much. They are forecasts, so it's the best we can do. And it's important because having those forecasts lets us start thinking ahead about where resources might need to be allocated. This year, it looks so far like the flooding we've seen so far in the US is lining up pretty well with where NOAA has forecasted we'll see different types of flooding this spring.

Colleen: So in looking at the spring flooding predictions in the midst of this coronavirus pandemic, tell me about the data that you looked at to kind of determine what areas might be hit with a flooding event and then have the overlay of the COVID-19 pandemic.

Kristy: So when NOAA releases its spring flooding forecast, it looks like a map of the country and different parts of the country are color-coded depending on whether they might see minor, moderate, or major flooding. Overall, this spring, they predicted that 23 states could see some level of flooding, so very widespread flooding that could potentially affect about 128 million people. So we took those areas that they had color-coded into those three different categories and we focused in just on the areas that could expect moderate or major flooding. So those are the two types of flooding that can require people to evacuate their homes. And we wanted to look at just those two because one of the first concerns that came to our mind in terms of flooding and coronavirus was whether people would be able to safely evacuate to some sort of emergency shelter given the fact that right now we're all trying to keep our distance from one another. If people are sick, they're either in a healthcare facility or isolating themselves at home, and that looks like something it'd be really hard to do given the way that shelters are typically set up.

So we took that moderate and major flooding data and then we asked, "Within these areas, are there specific counties or specific communities where the rate of coronavirus infections is expected to be high?" And to assess that piece, we used forecasts that were developed by two researchers at Columbia University, Jeffrey Shaman and Sen Pei. And what they did was looked at how the number of cases of COVID-19 has been growing in county by county in the US and then they use that data to calibrate a model that looked into the future for the next few months to say, "Okay, how many cases will there be, you know, by the end of April, by the end of May in each of these different counties?" So then we just pretty simply looked at where the flood risk was high and where the number of COVID-19 cases was expected to be high, or the percentage of COVID-19 cases was expected to be high.

Colleen: So what are the areas of biggest concern?

Kristy: So some of the areas that have the highest risk in terms of these two threats are eastern South Dakota, through the area around Sioux City. We also see major flooding risk and high coronavirus potential in parts of Iowa. And this is notable because many of these same areas were affected by severe flooding last year and are really still trying to recover. We've also seen...one of the areas that we identified as high risk was a part of Louisiana and that's part of the country that even since we developed these analyses, we've seen an explosion in the number of coronavirus cases in Louisiana. So, obviously, the places that are at highest risk are gonna be changing as the coronavirus plays out over the course of the season.

Colleen: Since this is unfolding as we speak in real-time, what are some of the emergency management practices that could be put into place now?

Kristy: So first and foremost, we can be using the best available data we have to try to understand where coronavirus and a risk like flooding or maybe extreme heat or maybe wildfire is going to present additional challenges. So staying on top of the latest projections for the coronavirus, the latest weather forecasts for flooding is gonna be extremely important right now. Another key piece is making sure that we're all doing everything possible to limit the spread of the coronavirus, so heeding local advisories and local guidance about what we should be doing as a community. And at the community level, those who are setting that guidance really need to be working to enforce it as well. And then in terms of what we can be doing to make sure that emergency shelters, if people are evacuating from flooding, are safe, we know that the Red Cross has been updating its guidance, specifically in light of the coronavirus this season. So they're starting to think about how their shelters need to look different and operate differently this season, which is a really encouraging sign.

[Break]

Colleen: What are some of those ways that they are operating differently?

Kristy: So what shelters will need to be doing differently is making sure that people aren't sitting together in a room close to one another. So one example here in San Francisco, I know a lot of effort is going into ensuring that the homeless population is safe during the coronavirus and they're using unused hotel space to give people who don't have homes right now, but need to be isolated from other people, space from one another and to make sure that they're safe. So that could be an important strategy in this time when hotels are under-occupied, we could potentially be using those spaces as emergency shelters so that people have the space they need from one another to stay safe.

Colleen: So in a rural or an agricultural area, when you have intensive spring flooding, what does that look like for people? Are there a lot of people evacuating areas? Do people try to shelter in place?

Kristy: So during a flooding event where people need to evacuate, you know, that can be a dozen people or it can be several hundred people depending on how severe the flooding is and where it's heading. Depending on the size of the community, that can be really overwhelming. So if you're in a very small community with, you know, not a lot of infrastructure around to support people who are evacuating, that can be very challenging. We also know that even in the face of potential extreme flooding, sometimes people choose not to evacuate. And that's the same...we see the same response when it comes to wildfires out here in California where I live. And when you're outside of that situation, it's easy to look at those decisions not to evacuate and wonder why on earth someone would make that decision. But it's important to recognize that evacuation comes with a cost. If you are not going to a shelter or if shelters are full, maybe you're looking at a week's worth of paying for a hotel room, and for some people, that is prohibitive. Other people may have pets that they can't take to a shelter or can't take to a hotel, and so they decide to shelter in place.

Colleen: Are there any areas right now that have already been hit that have a high infection rate?

Kristy: So far, we haven't seen any major flooding in places where there are high infection rates. There has been flooding already this season in parts of Ohio and parts of Kentucky and emergency responders there are concerned about how to address that flooding in light of the coronavirus concerns. But as the number of coronavirus cases continues to increase in the country and as we get deeper into this spring flooding season, there is a possibility that we will see those two threats colliding.

Colleen: So spring flooding is the first in what will be a series of climate-related challenges. Are you and your colleagues looking at how we'll cope with other climate-related impacts in the midst of the pandemic?

Kristy: We are looking at how other climate-related threats could intersect with the coronavirus. So starting in June, we'll be facing hurricane season and, you know, generally, what we see with hurricane season is that the worst part of it is in late summer and early fall of August and September. We're also taking a look at the wildfire season. Out here in California, we've had another dry winter, unfortunately, which does place us typically at higher risk for wildfires when that season gets started as well.

Colleen: And with wildfire season, you would essentially have the same types of issues it would be in terms of people evacuating and having places to go where we're not crowded in.

Kristy: That's right. So when wildfires are threatening a community, people do need to evacuate and many of them do end up in shelters or with family, friends in different communities, which right now is not great because we're not supposed to be visiting our friends and family that we don't live with immediately. But we also have the threat in California of the public safety power shutoffs. So this was a technique that was rolled out very widely last summer by PG&E, one of the largest utilities in the country. And essentially, what this is, is when the threat of wildfires is high, the utility is shutting off power and millions of people were affected by this last year. Sometimes the power shutoffs lasted for days, you know, three, four, or five days for many people. And when we think about having to shelter in place in our homes, to be working from our homes, to needing to have a week's worth of groceries on hand, to make sure we can feed our families, the thought of losing power is really scary. It was very disruptive for people last year, but I think in this moment it would be even more terrifying.

Colleen: Right. Extremely challenging to cope with.

Kristy: That's right.

Colleen: What other solutions should our listeners know about?

Kristy: When we're threatened by more than one thing at once, such as we are right now with flooding and coronavirus or other extreme weather and coronavirus, it's critical that we have federal coordination of the efforts to address those threats. So federal bodies like the Army Corps of Engineers, the National Guard, FEMA have a critical coordinating role to play to address shortfalls in hospital beds, assist in funding emergency shelters, etc. And over the last few years, we've seen the hollowing out of federal agencies such that organizations like FEMA are understaffed and overstretched. So in terms of what we can be doing in the long-term to prepare ourselves for the confluence of more than one threat at a time, we need to be ensuring that the federal government has the human resources that it needs in order to be responding to those threats.

Colleen: What role should the government play in this?

Kristy: FEMA has been tasked with the coronavirus response. So they're going to be responding over the course of the next few months to threats on all sorts of sides from the health side to the climate side. So we need to make sure that FEMA has the resources it needs to be operating on all those different fronts. But we also know that a lot of the decisions that are made on the ground when there's a natural disaster like a flood are made by state and local governments and they often involve coordination with organizations like the Red Cross. So up and down that chain from the level of an individual organization like the Red Cross up through the local and state government and then including the federal government, those sorts of actions need to be coordinated carefully to make sure that people are staying as safe as possible.

Colleen: So, Kristy, you've packaged this analysis with some really great maps and it is in a blog post that I will put the link to it on our webpage, but it's also blog.ucsusa.org and people can find the analysis there. Are you planning to do any updating of that analysis?

Kristy: We would like to be able to update the analysis as the projections for the number of coronavirus cases evolves. So the researchers who graciously supplied the data the first time around are working on improving their model and releasing new forecasts. They've already released an update just since we published the blog post last week. So we are hoping to do that for flooding and we are hoping to look at some of the other climate threats that we're facing in the coming months, including extreme heat and wildfires.

Colleen: Great. Well, Kristy, thanks so much for joining me. I know it's a little challenging. I think I heard a young one in the background at your house and maybe a dog. But thanks so much for taking the time to talk to me about this. And this is really important analysis and just thank you.

Kristy: Thank you so much for having me, Colleen, and for bearing with the kid and dog noise in the background.

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