New equation for water infiltration flow

New equation for water infiltration flow, which affects water modeling systems worldwide. The fields of agriculture, weather service and economics use such models regularly

Flooding caused more than $2.8 billion in damage across the United States last year. And despite the National Weather Service's best warning efforts, 38 people died.

But a University of Wyoming professor's recent work could help get the warning out more quickly and accurately.

Professor Fred Ogden, UW's Cline Chair of Engineering, Environment and Natural Resources, discovered a new equation for water infiltration flow, which affects water modeling systems worldwide. The fields of agriculture, weather service and economics use such models regularly, said Ogden.

"We have a project aimed at trying to develop a model to better predict the hydrology of the Panama Canal watershed," he said. "We need to adapt our equation to setting on tropical soil levels. We can then determine how changes might affect the water level in the Panama Canal, especially during drought."

Such modeling could assist with forecasting the United States' trade levels with Asia - 19 percent of shipping from Asia goes through the Panama Canal, Ogden said.

However, Ogden has not yet started one of the most important uses for his equation. He is going on a nine-month sabbatical beginning in September to work in the National Water Center in Tuscaloosa, Alabama - a joint project between the National Weather Service, the U.S. Geological Survey and the Federal Emergency Management Agency.

Ogden's formula will be integrated into ADHydro, a new national water modeling framework for doing real-time flood forecasting. After ADHydro is completed, every flood warning put out by the National Weather Service would use Ogden's equation.

Bob Steinke, a computer scientist and Ogden's close working associate, explained that while ADHydro can be used for predicting water flows for dangerous weather warnings, it also can be used for long-term planning.

"The goal of ADHydro is to simulate large watersheds - you basically want to figure out where the water goes, and if you change something in that watershed, how does it change where the water goes?" Steinke said.

Take, for example, clear-cutting some forests in the Rocky Mountains, Steinke said. The new model could be used to determine how the forestry affects the volume and timing of water flows to streams and how that could eventually affect the amount of water in Lake Powell over the next decade.

"The end goal is to give water resource managers a tool to make long-term decisions," he said.

Ogden's equation could replace the Richards equation, created by Lorenzo Richards in 1931, which was used to determine how water interacts with soil - for example, how much water is absorbed, how much is evaporated and how saturation could affect surface flow. The main advantage is simplicity and speed, Ogden said.

"The original 1931 equation is what's called a partial differential equation," he said. "It's kind of like juggling a whole bunch of balls, and it makes the solution a lot harder. Our equation is a differential equation, like juggling one ball."

Ogden's equation also is almost guaranteed to produce useful data. The Richards equation is so complex it might not even produce an answer in certain situations. Ogden's equation also can be run about 100 times faster than the Richards equation on a supercomputer - technology which Ogden gives partial credit to for his success.

"I was telling (my brother) about this discovery, and I just said, 'John, I can't believe that, of all the bright people that have worked on this problem, I'm the guy that figured it out,'" Ogden said. "My brother ended up calling me back and said, 'I'm not surprised you figured it out, because you're from the first generation of people who thought about solving this problem with a computer.'"

Other professors and experts analyzing the Richards equation were using paper and pencil.

Steinke said collaborating with Ogden was a great way to find the new equation and proof it.

"He tends to be the big thinker, and I work out some of the details," Steinke said. "Our different backgrounds and tech areas were a great fit."

While the equation is online for free and available to anyone, Ogden said it might take some time to completely integrate into current water modeling.

"The people who get it say 'Congratulations,'" he said. "The people who are skeptical say, 'Yeah, right.' The people who are beyond skeptical have a hard time believing the farm kid from Lamar, Colorado, who went to college at little old University of Wyoming could figure this (equation) out."

Source: Wyoming News

Read More Related Content On This Topic - Click Here

Media

Taxonomy

• Integrated Watershed Management
• Consumption
• International Disaster Planning, Preparedness and Response