From isnv@ars-grin.gov Tue May 2 13:40:52 2000 Date: Tue, 2 May 2000 09:00:24 -0400 From: ARS News Service To: ARS News List Subject: Computer Model Illustrates Water Movement Through Soil STORY LEAD: Easy-to-Use Computer Model Helps Illustrate Water Movement Through Soil ___________________________________________ ARS News Service Agricultural Research Service, USDA Kathryn Barry Stelljes, (510) 559-6069, stelljes@asrr.arsusda.gov 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' monthly magazine, and can be found on the World Wide Web at: http://www.ars.usda.gov/is/AR/archive/may00/flow0500.htm Demonstration versions of the model are online at: http://www.ussl.ars.usda.gov/MODELS/HYDRUS2D.HTM and http://www.mines.edu/research/igwmc/zipfiles 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, rvang@ussl.ars.usda.gov. ___________________________________________ This item is one of the news releases and story leads that ARS Information distributes on weekdays to fax and e-mail subscribers. You can also get the latest ARS news on the World Wide Web at www.ars.usda.gov/is/pr/thelatest.htm. * Feedback and questions to ARS News Service via e-mail: isnv@ars-grin.gov. * ARS Information Staff, 5601 Sunnyside Ave., Room 1-2251, Beltsville MD 20705-5128, (301) 504- 1617, fax 504-1648.