UNDERSTANDING AND PREDICTING THE IMPACT OF AGRICULTURE ON THE ENVIRONMENTAL INTEGRITY OF MANAGED WATERSHEDS
Location: Water Quality and Ecology Research
Title: AnnAGNPS – A United States Department of Agriculture Watershed Conservation Management Planning Tool for Non-Point Source Pollution Control
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 20, 2009
Publication Date: September 7, 2009
Citation: Bingner, R.L., Locke, M.A. 2009. AnnAGNPS – A United States Department of Agriculture Watershed Conservation Management Planning Tool for Non-Point Source Pollution Control. Water Quality Research to Evaluate the Effects of Agricultural Conservation Practices Utilized in the United States and India Workshop Proceedings. Allahabad Agricultural Institute–Deemed University, Allahabad, India. p. 8-9.
Interpretive Summary: Abstract Only - Interpretative Summary not required.
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. Non-point source 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 United States Department of Agriculture (USDA) Annualized Agricultural Nonpoint Source model (AnnAGNPS) (Bingner and Theurer, 2001b) was developed to perform these necessary evaluations to assist in watershed conservation management planning typically performed by action agencies, such as the USDA–Natural Resources Conservation Service, for non-point source pollution control.
Since AnnAGNPS is designed to analyze the impact of non-point source pollutants from predominately agricultural watersheds on the environment, other models that simulate additional processes have been integrated with AnnAGNPS. These integrated models have been developed within the AGNPS suite of modules (Bingner and Theurer, 2001c). Each module provides information needed by other modules to enhance the predictive capabilities of each. The modules in AGNPS include: (1) AnnAGNPS, a watershed-scale, continuous-simulation, pollutant loading computer model designed to quantify & identify the source of pollutant loadings anywhere in the watershed for optimization & risk analysis; (2) Center for Computational Hydroscience and Engineering – One Dimensional channel model (CCHE1D) (Wu and Vieira, 2000) is a stream network program designed to integrate the impact of upland loadings and channel characteristics on the evolution of the stream channel; (3) Conservational Channel Evolution and Pollutant Transport System (CONCEPTS) (Langendoen et al, 1998, and Langendoen, 2001), a stream corridor computer model designed to predict & quantify the effects of bank erosion & failures, bank mass wasting, bed aggradation & degradation, burial & re-entrainment of contaminants, and streamside riparian vegetation on channel morphology and pollutant loadings; (4) The Stream Network TEMPerature model (SNTEMP) (Theurer et al, 1984), a watershed-scale, stream network, water temperature computer model to predict daily average, minimum, & maximum water temperatures; (5) The Sediment Intrusion & Dissolved Oxygen (SIDO) model (Alonso et al, 1996), a set of salmonid life-cycle models designed specifically to quantify the impact of pollutant loadings on their spawning & rearing habitats as well as include other important life-threatening obstacles; and (6) an economic model that determines the net economic value of Pacific Northwest salmonids restored to either the commercial or recreational catch.
As part of the input data preparation process there are a number of modules that support the user in developing the needed AnnAGNPS databases. These include: (1) the TOpographic PArameteriZation program (TOPAZ) (Garbrecht and Martz, 1995), to generate cell and stream network information from a watershed digital elevation model (DEM) and provide all of the topographic related information for AnnAGNPS. A subset of TOPAZ, TOPAGNPS, is the set of TOPAZ modules used for AGNPS. The use of the TOPAGNPS generated stream network is also incorporated by CONCEPTS to provide the link of where upland sources are entering the channel and then routed downstream; (2) The AGricultural watershed FLOWnet generation program (AGFLOW) (Bingner et al, 1997; Bingner et al, 2001a) is used to determine the topographic-related input parameters for AnnAGNPS and to format the TOPAGNPS output for importation into the form needed by AnnAGNPS; (3) The Generation of weather Elements for Multiple applications (GEM) program (Johnson et al, 2000) is used to generate the climate information for AnnAGNPS; (4) A graphical input editor that assists the user in developing the AnnAGNPS database (Bingner et al, 1998); and, (5) A geographical information system (GIS) interface program to facilitate the development of the input for AnnAGNPS. An output processor program has been developed that can be used to help analyze the results from AnnAGNPS by generating a summary of the results in tabular or GIS format.
On-going enhancements to AnnAGNPS have been and will continue to be developed for use with national and international watershed projects, including: (1) enhanced ephemeral gully and landslide components; (2) enhanced snowfall, snowmelt, and soil temperature capabilities; (3) enhanced subsurface flow and pollutant transport components; (4) improved GIS user interface; and (5) expansion of model databases.
AnnAGNPS is available through the Internet WEB address: