In 1997, NASA and the Japan Aerospace Exploration Agency (JAXA) launched a satellite capable of measuring equatorial precipitation levels in sub-monthly time intervals.
Nearly 20 years later, two University of Maryland (UMD) researchers are utilizing data from the satellite’s associated project, the Tropical Rainfall Measuring Mission (TRMM), to combat the financial and loss of life issues caused by flooding.
Floods are one of the most common and costly types of severe weather, according to the Red Cross. Researchers estimate the average annual cost of global flood damage in 2005 was $6 billion. By 2050, those estimates could increase to more than $1 trillion, according to a 2013 study published in the journal Nature Climate Change.
Floods also upset the lives of millions of people each year. In China alone, major flooding disasters in 1991 and 1998 affected a combined 448 million people, according to statistics portal and aggregate Statistica.
For Drs. Robert Adler and Huan Wu, both researchers at UMD’s Earth System Science Interdisciplinary Center (ESSIC), these widespread economic and social impacts underscore the need for timely and accurate flood information.
To provide such information, Adler and Wu have developed the Global Flood Monitoring System (GFMS).
The system itself is based on 13 years of precipitation data linked to hydrology models that analyze water cycle factors like rainfall, runoff and absorption rates. Water level thresholds were subsequently created for a variety of terrains, topologies, and regions that compare current precipitation data projections in order to detect flooding.
“It’s the first and it’s at the moment, one of a kind,” Adler said. “It’s the only system that uses satellite precipitation information and does this flood estimation on a quasi-global basis. Other people have talked about it, but we’re really the first and only ones.”
Specifically, GFMS analyzes the Earth from 50 degrees north to 50 degrees south of the equator and projects the data on a gridded map of the globe. Updates down to a one kilometer scale are provided every three hours. The interactive map available on website flood.umd.edu, allows users to zoom into specific regions, select the map’s time scale from daily to monthly, and view individual parameters such as rainfall amounts, stream flow, and flood locations.
Though scientists and colleagues at NASA’s Goddard Space Flight Center made up a large portion of the GFMS’s initial site visitors, Wu stated that people in more than 100 countries have utilized the page since February 2014.
International relief organizations like the Red Cross and USAID have also discovered the value of the GFMS, using its map in tandem with population maps to determine which flood-stricken areas hold the greatest number of people in need.
According to Wu, one of the most significant strengths of GFMS is its ability to offer a continuous stream of data, which bypasses many of the problems faced by other forms of precipitation and flood detection.
“When floods come, most of the time there are a lot of clouds, and they cannot really see,” Wu said. “And also they can’t see through the trees. So we use the model to fill that gap. There are many cases where the system we developed is unique [and] is the only information for the relief.”
While the prototype has provided demonstrated benefit to both the scientific and humanitarian aid communities, Adler feels it’s far from complete.
“It’s not fully mature; it’s not the final version,” Adler said. “There’s still lots of development and improvement to be made.”
Adler is hopeful that with additional users, time, and funding, the system’s maturation process, including improvements to the GFMS website as well as refinements to general system algorithms, will continue and its potential fully realized.