Skip to footer

Can we predict floods from space?

Using satellite data of how much water is stored in river basins, researchers say they have determined a new way to predict which rivers are likely to flood.

|
J.T. Reager
Wetter-than-average conditions detected by the GRACE satellite before the Missouri River flooded in March 2011.

Researchers have figured out a new way to predict which rivers are most at risk of dangerous flooding.

To do so, they measured how much water was stored in a river basin months ahead of the spring flood season.

"Just like a bucket can only hold so much water, the same concept applies to river basins," said lead study author J.T. Reager, an earth scientist at the University of California, Irvine. When the ground is saturated, or filled to its brim, conditions are ripe for flooding. [Top 10 Deadliest Natural Disasters in History]

Reager and his colleagues looked back in time using satellite data, and measured how much water was soaking the ground before the 2011 Missouri River floods. The researchers found their statistical model strongly predicted this major flood event five months in advance. With less reliability, the prediction could be extended to 11 months in advance, the researchers said.

"This gives the background on what's on the ground before the rain even gets there," Reager said.

The findings were published today (July 6) in the journal Nature Geoscience.

The 2011 Missouri River floods lasted for months, closing interstates, shutting down nuclear plants and scouring farmland. The National Weather Service issued flood alerts in April, a month before flooding began.

Reager hopes his new method will eventually help forecasters prepare reliable flood warnings several months earlier. "It would be amazing if this could have a positive effect and potentially save lives," he said.

The researchers relied on NASA's twin GRACE satellites to diagnose a region's flood potential. As the satellites circle the Earth, changes in gravity slightly perturb their orbit. These tugs are proportional to changes in mass, such as a buildup of water and snow. (GRACE was originally designed to track melting in the ice sheets.)

The team used GRACE to look at all potential water sources, including snow, surface water, soil moisture and groundwater. "This gives us a more accurate interpretation of what's happening on the ground," Reager said.

So far, the method has only been tested when the team looked back at past floods. And it only works with certain types of floods — it can't help predict flash floods caused by sudden rains, such as India's monsoonal flooding, Reager said. "GRACE can only see this slow saturation flooding," he said.

There's also a three-month lag before the researchers can obtain data from the GRACE satellites, which means potential flood predictions using this method are limited to only two or three months in advance, Reager said. That's about the same amount of advance warning that on-the-ground measurements currently provide. NASA is, however, working on ways to speed up its data delivery to 15 days, he said.

Email Becky Oskin or follow her @beckyoskin. Follow us @livescience, Facebook & Google+. Original article on Live Science.

Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.
editor@csmonitor.com
Subscribe
Mark Sappenfield
Editor

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

Subscribe to insightful journalism

QR Code to Can we predict floods from space?
Read this article in
https://www.csmonitor.com/Science/2014/0707/Can-we-predict-floods-from-space
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe