Easy-to-Use Computer Model Helps
Illustrate Water Movement Through Soil
By Kathryn Barry
May 2, 2000
A user-friendly, sophisticated computer
model developed by the Agricultural Research
Service has helped engineers, scientists and students worldwide understand
how water and chemicals move in soil and groundwater.
HYDRUS allows agricultural engineers to design irrigation systems that
provide optimal water to crops while minimizing the transport of fertilizers
and pesticides to groundwater. Landfill designers have used the program to
ensure their facilities do not release contaminants.
Dozens of scientists and students contributed to HYDRUS, which was developed
at ARS' George E. Brown, Jr., Salinity
Laboratory in Riverside, Calif. ARS soil scientist Rien van Genuchten and
University of California civil engineer Jirka
Simunek are lead authors of the computer program.
The model continues to evolve, thanks to a cooperative research and
development agreement with the Colorado School
of Mines' International
Ground Water Modeling Center (IGWMC) in Golden. IGWMC distributes the
model, provides hands-on help to users, runs short-courses on the model, and
gives feedback to ARS so that the researchers can improve HYDRUS.
So far, IGWMC has sold more than 500 copies of the model worldwide, and has
conducted courses on the model in the U.S., Europe and Australia.
HYDRUS provides an easy-to-use, Windows-based format. It displays results
visually by means of graphs or contour lines, instead of as columns of numbers.
Animation can illustrate how a fertilizer or other chemical would move through
the soil and possibly into groundwater.
An article describing this work appears in the May issue of
Agricultural Research, ARS'
Demonstration versions of the model are online at:
ARS is the chief research agency of the U.S.
Department of Agriculture.
Scientific contact: Rien van Genuchten, Soil Physics and Pesticide
Research Unit, ARS George E. Brown, Jr., Salinity Laboratory, Riverside Calif.,
phone (909) 369-4847, fax (909) 342-4964,