Originally published on the UGA Institute for Disaster Management blog.

Climate change is driving more inland and coastal flooding across the U.S., sometimes in communities with no history of flooding. How does a heating planet contribute to more flooding, and what can communities do to stay safe and prepare?

With expertise in geography and climate science, Michelle Ritchie, an assistant professor in the Institute for Disaster Management (IDM) at UGA’s College of Public Health, explains how climate change has made flooding worse and how communities are adapting.

How is climate change linked to heavy rainfall?

All of our rains come down as part of the hydrologic cycle. So, anywhere in that process, whether water has just landed on the surface of the earth or it’s saturated down through the soils, all of the places where water is, it’s part of the hydrologic cycle. And that cycle, under the influence of climate change, has sped up.

A warmer atmosphere means that the atmosphere can hold more water, and that’s what’s helping to speed up that cycle. So, more evaporation is occurring, which is why there’s also more droughts at the same time as more flooding. It seems very counterintuitive, but it’s because that cycle has sped up, so the atmosphere is able to dump that much more rain down.

Why are these flash floods dangerous?

Flash floods begin and end within a matter of minutes. This is part of what makes them so dangerous. We generally know where floods are going to occur, and if we have a hurricane coming in, we have time to predict that and where additional flooding may be seen. But because the hydrologic cycle has sped up, we may have less awareness of where those pockets of rainfall might occur that lead to secondary hazards, for example, like flash flooding. So, places that haven’t historically had flash floods might begin see them. The other issue to consider once a flash flood hits an area is access. If you’re having flash floods, it could cut off electricity and it could cut off the ability to go in and out of an area, including for emergency services, basically until that water subsides. Ultimately, preventing development in floodplains and other flood-prone areas is one way to reduce community exposure to hazards.

What are some ways flooding can impact health that people may not think about?

Some of those health risks present after the flood, not just during the flood. We tend to see a lot of folks walking around in the flood water after storms, but there are a lot of things in that water, things that were in the soil or maybe were in folks’ septic tanks that have now flooded. So, it’s not safe to be wading through, and flood waters are typically very turbid, which makes them nearly impossible to see through. You don’t know where you are walking or what you might be walking on. Also, once the flood water recedes, if your basement was flooded, for example, that means you might have ideal conditions for mold to grow.

Are there long-term health risks associated with flooding like we’ve seen in the U.S. this summer?

Absolutely. One of the primary things I study in looking at climate change is how individuals and households adapt. What we find is that your sense of place — that very personal process that ties together your understanding of yourself and your relation to place — it can essentially be ripped apart after an event like a devastating flood. So, how you put that sense of place back together and maintain it into the future is important, not just on an individual or household scale but on a community scale. It is interesting because we have all these numbers of how many houses were impacted by flooding and how much it cost, yet we don’t really have a good understanding of what that longer lasting ripple effect of the trauma is.

How can communities or healthcare systems prepare for future flood events?

If this is an area that hasn’t historically experienced floods, or it’s been a long time since the last flood, or even on the flip slide if floods are so common that nothing beyond the typical is planned for, you’re likely not addressing flood risk as fully as you could be. If you’re not ready for a flood and it comes, especially in a healthcare facility, that means you probably haven’t thought about what to do, which is really the bigger danger than the flood itself. You need to have a plan in place and have practiced that plan. This is one of the big things that the folks at IDM are actively working on, which is training long-term care facilities in basic disaster preparedness. So, if you do those training sessions and actually go through the motions, you’re creating muscle memory. You know what to do, you know where your resources are, and so you’re much less likely to face disastrous consequences when the flood hits.

Making sure that folks evacuate when they’re advised to is also important because you really only need a few inches of water to get swept off your feet and only a few more inches beyond that to sweep your car off its wheels, and then you’re in some really big trouble, right?

Will flooding get worse?

Yes, in general, I think flooding events will get worse, but it doesn’t necessarily mean that the impacts of them need to become disastrous. So, if we can start learning from these floods and applying an array of mitigation and adaptation strategies where they’re needed, then we can lessen the impacts of future flooding.

This is the path that we’re on. The global climate will continue to warm, so now is the time to prepare and now is the time to plan, especially among and for our vulnerable populations, who typically take the brunt of a lot of climate change impacts, like secondary impacts of more or worsened flooding.

Posted on September 12, 2022.