Are there different types of flooding?

[music fades in]

Welcome to CoreFacts, where we're always short on time and big on science. I'm Steve Sobieszczyk. Let's get right to it, today's question is.

Are there different types of flooding?

There are two basic kinds of floods, flash floods and the more widespread river flooding. Flash floods generally cause greater loss of life and river floods generally cause greater loss of property. A flash flood occurs when runoff from excessive rainfall causes a rapid rise in the stage of a stream or normally dry channel. Flash floods are more common in areas with a dry climate and rocky terrain because lack of soil or vegetation allows torrential rains to flow overland rather than infiltrate into the ground. River flooding is generally more common for larger rivers in areas with a wetter climate, when excessive runoff from longer-lasting rainstorms and sometimes from melting snow causes a slower water-level rise, but over a larger area. Floods also can be caused by ice jams on a river, or high tides. However, most floods can be linked to a storm of some kind.

And now you know. Join us again tomorrow as we'll give you yet another new CoreFact. If you're interested in previous CoreFacts, or would like to check out CoreCast, our in-depth science podcast, browse over to usgs.gov/podcasts. If you would like to contact us here at the show or submit a question you think we should answer on the air, you can email us at corefacts@usgs.gov or leave us a voicemail at 703-648-5600. Remember, long distance fees do apply.

The USGS CoreFacts is a product of the U.S. Geological Survey, Department of the Interior.

[music fades out]