Preface and Acknowledgments

Preface

Wind erosion is a serious problem on agricultural lands throughout the United States as well as the world. The ability to accurately predict soil loss by wind is essential for, among other things, conservation planning, natural resource inventories, and reducing air pollution from wind blown sources. The Wind Erosion Equation (WEQ) is currently widely used for assessing average annual soil loss by wind from agricultural fields. The primary user of WEQ is the United States Department of Agriculture, Natural Resources Conservation Service (USDA-NRCS). When WEQ was developed more than 35 years ago, it was necessary to make it a simple mathematical expression, readily solvable with the computational tools available. Since its inception, there have been a number of efforts to improve the accuracy, ease of application, and range of WEQ. Despite these efforts, the structure of WEQ precludes adaptation to many problems.

The USDA appointed a team of scientists to take a leading role in combining the latest wind erosion science and technology with databases and computers, to develop what should be a significant advancement in wind erosion prediction technology. The Wind Erosion Prediction System (WEPS) incorporates this new technology and is designed to be a replacement for WEQ.

Unlike WEQ, WEPS is a process-based, continuous, daily time-step model that simulates weather, field conditions, management, and erosion. WEPS 1.0 consists of the WEPS science model with a user-friendly interface that has the capability of simulating spatial and temporal variability of field conditions and soil loss/deposition within a field. WEPS 1.0 can also simulate simple field shapes and barriers on the field boundaries. The saltation/creep, suspension, and PM10 components of eroding material also are reported separately by direction in WEPS 1.0. WEPS 1.0 is designed to be used under a wide range of conditions in the United States and is adaptable to other parts of the world. For further information regarding WEPS contact:

WEPS

USDA-ARS Engineering and Wind Erosion Research Unit

1515 College Avenue

Manhattan, Kansas 66502

Phone:	785-776-2726

E-mail:	weps@weru.ksu.edu

URL:	http://www.weru.ksu.edu/weps

Acknowledgments

The Wind Erosion Prediction System (WEPS) resulted from the work of many individuals representing several agencies and institutions. In particular, appreciation is extended to the WEPS Core Team members:, D.V Armbrust (retired), J.D. Bilbro (retired), G.W. Cole (retired), A.A. Durar, F. Fox, D.W. Fryrear (retired), R.B. Grossman, L.J. Hagen (retired), L. Lyles (retired), A. Retta, A. Saleh, H.H. Schomberg, H.R. Sinclair, E.L. Skidmore (retired), J.L. Steiner, J. Tatarko, P.W. Unger (retired), S. Van Donk, and T.M. Zobeck; the Agency liaisons to the Core Team, including: M.S. Argabright, NRCS (retired), H. Bogusch, NRCS, R. Dunkins, EPA, and C. Voight, BLM; the ARS NPL, including: C.R. Amerman (retired),W.D. Kemper (retired), and Mark Weltz; and NRCS leaders including K. Flach (retired), M. Hubbs, A. King (retired), C. Lander (deceased), S. Rawlins (retired), D. Schertz (retired), M. Sporcic, G.L.Tibke (retired), and D. Woodward.

Gratitude is also expressed to the many cooperators and other individuals who have contributed to the development of WEPS through their valuable research, criticisms, testing, and comments. These individuals include: J.K. Aase, A. Black, W. Blackburn, P. Bullock, D.J. Ding, G. Foster, D.A. Gillette, J. Gregory, J.R. Kiniry, D. Koeltzow, J. Laflen, J.A. Lamb, F. Larney, J.B. Layton, M.J. Lindstrom, S.D. Merrill, C. Meyer, N. Mirzamostafa, D.L. Mokma, A. Moulin, A. Nicks, K.N. Potter, R. Savabi, K. Saxton, J. Stout, L. Sutherland, E.D. Vories, and J. Williams. The work of L. Ascough, W. Gu, A. Hawkins, S. Kaul, S. Kota, S. Liu, W. Rust, and M. Uttarwar is also greatly appreciated.

Recognition is given to the support of many agencies and universities that made WEPS a reality. These include the USDA Agricultural Research Service, USDA Natural Resources Conservation Service, the US Department of Interior - Bureau of Land Management, the US Forest Service, the US Environmental Protection Agency, the US Army Corps of Engineers, and Kansas State University.

The contribution of the NRCS state and field offices and other individuals who participated in the WEPS validation studies is also recognized.

Finally, acknowledgment is made of the many other individuals who have made this release of WEPS possible by reviewing this document and those who contributed through fundamental research on which many of the underlying concepts of WEPS are based.

Larry Wagner

WEPS Project Leader

USDA-ARS-EWERU

Manhattan, Kansas USA