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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #202756
Title: Watershed Conservation Management Planning Using AGNPS

Author
item Bingner, Ronald - Ron
item THEURER, FRED - USDA, NRCS
item MOORE, DANIEL - USDA, NRCS

Submitted to: Proceedings of the Sino-American Workshop on Advanced Computational Modeling in Hydroscience and Engineering
Publication Type: Proceedings
Publication Acceptance Date: 11/10/2006
Publication Date: 11/25/2006
Citation: Bingner, R.L., Theurer, F.D., Moore, D.S. 2006. Watershed Conservation Management Planning Using AGNPS. In: Proceedings of the Second Sino-American Workshop on Advanced Computational Modeling in Hydroscience and Engineering, November 25-26, 2006, Beijing, China. CD-ROM.

Interpretive Summary: A watershed scale assessment of the effect of conservation practices on the environment is critical when recommending best management practices to agricultural producers. The environmental benefits of these practices have not been widely quantified at the watershed scale, which would require extensive monitoring studies. Pollutant loading allocations established without comprehensive studies will likely require treatment of lands that will contribute little to load reductions and insufficient treatment of higher contributing lands. The US Department of Agriculture’s (USDA) Annualized Agricultural Nonpoint Source model (AnnAGNPS) was developed to perform these necessary evaluations to assist in watershed conservation management planning. An enhancement to the model is described that accounts for additional sources of sediment within a watershed that occurs from ephemeral gully erosion. An application of the model utilizing the ephemeral gully enhancement determined that 36% of the total sediment load from a Kansas watershed resulted from ephemeral gully erosion. An additional enhancement to the model is discussed that addresses frozen precipitation and soil conditions that contributes to the high-priority needs of USDA Conservation Effect Assessment Project (CEAP) watershed studies. Watershed studies utilizing AnnAGNPS provides critical information to management that will assist in assessing the effectiveness of USDA’s conservation programs as a result of the various Farm Bills enacted since 1985.

Technical Abstract: A watershed scale assessment of the effect of conservation practices on the environment is critical when recommending best management practices to agricultural producers. The environmental benefits of these practices have not been widely quantified at the watershed scale, which would require extensive monitoring studies. Pollutant loading allocations established without comprehensive studies will likely require treatment of lands that will contribute little to load reductions and insufficient treatment of higher contributing lands. The US Department of Agriculture’s (USDA) Agricultural Nonpoint Source model (AGNPS) was developed to perform these necessary evaluations to assist in watershed conservation management planning. AGNPS is a suite of computer models developed to assist the user with quantifying the impacts of agricultural nonpoint source pollution on water quality and the environment. Enhancements to AGNPS have been and will continue to be developed for use with the USDA Conservation Evaluation and Assessment Project (CEAP), which includes: (1) enhanced ephemeral gully components; and (2) enhanced snowfall, snowmelt, and soil temperature capabilities. The objectives of this paper are to discuss these enhanced components and the overall application of AGNPS within watershed projects.