 Abstract flooding is a major global threat, affecting millions of people around the world. To better understand how vulnerable different regions are to floods, researchers analyzed data on 1.2 million river reaches around the globe. They found that topography and drainage area were key factors in determining the sensitivity of flood plains to different types of floods. Areas prone to frequent, low-magnitude floods had more evenly spread populations, while areas prone to rare, high-magnitude floods had higher concentrations of people living there. These results suggest that people have adapted to the risk of low-magnitude floods, but may not be prepared for the increased risks posed by climate change. This article was authored by Laura Devitt, Jeffrey Neal, Gemma Coxson, and others.