Vadose zone water is water that travels from the surface as rainwater all the way down to the water table. Since 1931, the equation used to calculate vadose zone water was the Richards Equation. However, researchers have always known the equation was difficult for computers to model and they have longed for a better one. But better expressing the vadose zone water quantity than the Richards Equation proved elusive for decades.
At last, Fred Ogden, professor of engineering at the University of Wyoming, found a superior equation, according to a release. Solving the new equation proved easier for computers than the Richards Equation. In addition, results of the new equation were tested by a supercomputer and found to be nearly identical.
The new equation will greatly improve water movement estimates for researchers in many fields, including climate science, agriculture, hydrology and soil science. The work of city planners and irrigators is also expected to benefit.