Simultaneous real-time flood forecasting of streams across the nation is now possible

Lawrence Goodwyn

Every year, over 200 people die in the US from flash floods. New research by UT professors could make flood forecasting more efficient and help prevent these deaths. 

David Maidment, UT civil engineering professor and Hussein M. Alharthy Centennial Chair in Civil Engineering, and his team developed The National Water Model, a big data supercomputer capable of mapping the topology of the nation.

The National Water Model, which was initiated on August 16th, simultaneously forecasts 2.7 million streams, rivers, and creeks across the nation, targeted at mapping and reducing the risk of flooding accidents, a leap nearly 700 times better than previous forecasting of only 4000 reaches.

A reach is a general term used to describe a length of stream or river surrounded by a local drainage area.

Maidment said the machine delivers measurements down to the meter, which allows for precise predictions. He said it also helps emergency responders communicate and send accurate messages to civilians.  

“Before this, some predictions could be way off because they were not down to the meter level, leaving unexpecting populations clueless as to what to do in the midst of a flooding event,” Maidment said.  

The machine uses GIS, or geographical information systems, along with 8,000 drainage points from the U.S. Geological Survey points, to accurately model river reaches across the nation.

Shaowen Wang, a geography and GIS professor at University of Illinois at Urbana Champaign, oversaw the building of the GIS modeling data for the project. Wang said GIS is important to flood prediction because knowing what specific topological features look like helps determine where rain will collect and possibly cause flooding.

“It enabled us to think of the whole country as one big system — atmosphere to the ocean and coast to coast,” Maidment said. 

The team also worked to improve HAND, or Height Above Nearest Drainage, data that is highly underused in some regions. Wang said HAND is the elevation difference between land and streams that identifies local drainage points and determines where water could flow. 

Maidment said that because flooding can lead to many fatalities, he wants to better prepare communities for approaching weather. He said there are only a few locations in Texas where data is being collected, but there need to be more.

“There’s about six official forecast points in Austin, one is in the Colorado River, another in the Blanco River — these are just a few dots in our landscape, in our system, there’s 1000 miles of streams of forecast in Travis County alone,” Maidment said. 

Wang said applying the modeling system to the U.S. was no simple feat because unlike other countries, the U.S. is made up of extremely diverse terrains. 

Wang said that China could be the next place to implement the modeling technology, helping them to utilize their land and better protect their citizens from flooding risks.

In the wake of recent flooding tragedies, Maidment hopes to curb the amount of damage taken from these events.

“Some of these people can be saved, with advanced technology, better forecasting, it doesn’t have to occur like it has been,” Maidment said. 

Maidment will continue improving the technology behind the model and hopes to see it expand. 

“We need a great deal more flood intelligence than we’ve had.” Maidment said. ”Half the counties in Texas don’t have flooding forecasting — and the National Water Model will bring that to them.”