Satellites reveal possible catastrophic flooding months in advance

A press release from the University of California (Irvine): Data from NASA satellites can greatly improve predictions of how likely a river basin is to overflow months before it does, according to new findings by UC Irvine. The use of such data, which capture a much fuller picture of how water is accumulating, could result in earlier flood warnings, potentially saving lives and property. The research was published online Sunday in the journal Nature Geoscience.

A case study of the catastrophic 2011 Missouri River floods showed that factoring into hydrologic models the total water storage information from NASA’s Gravity Recovery & Climate Experiment mission – including groundwater accumulation below the surface – could have increased regional flood warning lead times from two months to as long as five months.

A review of the 2011 Columbia River floods found that warnings could have been issued three months before they occurred. Comprehensive underground measurements are not currently part of predictive models, which typically take into account river flow rates and some snowfall amounts.

“GRACE data contain important hydrologic information that is not currently being utilized to estimate regional flood potential,” said lead author J.T. Reager, who did the work as a UCI postdoctoral researcher and recently joined NASA’s Jet Propulsion La
boratory as a research scientist. “This could significantly increase flood prediction lead times within large river basins.”

Inland flooding causes an average of 133 deaths and $4 billion in property losses per year in the U.S., according to the National Weather Service. Earlier flood predictions could help water managers better plan for possible water diversion and evacuation strategies.

The two GRACE satellites provide a means to observe monthly variations in total water storage within large river basins based on measurements of tiny changes in Earth’s gravitational field: When the amount of water stored in a region increases, the gravitational pull from that area increases proportionately – which the satellites can detect....

Artist's conception of the GRACE satellites at work, via NASA