Model Provides Major Advance
in Controlling Water Erosion
By Hank Becker
April 30, 1997
WASHINGTON, April 30--A new computer model gives land
managers, environmentalists, educators and policy makers worldwide a powerful
tool to help combat water erosion of cropland, a
U.S. Department of Agriculture scientist says.
"WEPP--short for the Water Erosion Prediction Project--represents
a major advance in our ability to evaluate how the different ways we use the
land can affect soil erosion by water," said C. Richard Amerman, national
program leader for soil erosion at USDA's Agricultural Research Service in
WEPP is a project of the USDA's Forest Service, Agricultural
Research Service and Natural Resources Conservation Service and the U.S.
Department of the Interiors Bureau of Land Management. WEPP is the result
of 10 years of research by dozens of USDA and USDI scientists, plus cooperators
from universities and several foreign countries.
In tests, the model's predictions have been validated by 1,000
plot-years of data on water runoff and erosion from 12 sites and 15 watersheds
around the United States. A plot- year is a years worth of data on a
specific plot of land.
"WEPP provides needed new technology to better assess how much
erosion occurs and how much sediment is deposited on cropland, rangeland and
forest land," said ARS agricultural engineer John M. Laflen, the WEPP project
leader. Now based at the agency's National Soil Tilth Laboratory in Ames, Iowa,
Laflen played a lead role in developing and testing the erosion prediction
technology at the ARS National Soil Erosion Research Laboratory at West
"WEPP predicts rill and interrill erosion separately, which other
prediction tools are not designed to accommodate," Amerman noted. Rill erosion
is caused by water running over the soil, while interrill erosion is caused by
raindrop impact and splash.
The researchers describe the latest stages of WEPPs
development and testing in an article in the April issue of Agricultural
Research, ARS monthly publication. The story can be viewed on the
World Wide Web at:
The Forest Service has already used the model to address
site-specific erosion problems, such as the impact of timber harvesting on
sediment in streams. The BLM will use WEPP in developing strategies to control
erosion from rangelands.
The WEPP model has already been demonstrated to groups in Russia,
Costa Rica, Canada, China, Austria, Portugal, Mexico, India, Italy, Ukraine,
Brazil, Uganda, Australia and Belgium. "WEPP has been used on every continent
but Antarctica," said Laflen.
Users can obtain the most current WEPP model release,
documentation, information and patches on the World Wide Web at:
The model is also available from Laflen on a multi-media CD-ROM.
Scientific contact: John Laflen, ARS-USDA National Soil
Tilth Laboratory, 2150 Pammel Dr., Ames IA 50011, phone (515) 294-8327; fax
294-8125, e-mail firstname.lastname@example.org.