2008 Annual Report 1a.Objectives (from AD-416) Principal focus of the Conservation Effects Assessment Project (CEAP) effort is to produce national and regional assessments of environmental benefits of conservation programs to support policy decision and program implementation on crop and grazing lands by the Natural Resources Conservation Service (NRCS). 1b.Approach (from AD-416) Develop a relational database (Hydrologic Unit Model of the United States: HUMUS) from ARS historical watershed data and data from other public sources (i.e., USGS, NRCS, EPA, BLM, USFS, NASA, and NOAA). This relational database will then be use to evaluate and improve the ARS Soil Water Assessment Tool (SWAT) model. The validated SWAT model will then be applied to estimate the impact of conservation practices on water quality, soil quality, sustainability of rangeland ecosystems, and wildlife habitat in regional and national assessments in partnership with the NRCS. Documents SCA with U of Nevada-Reno. 3.Progress Report We held two formal workshops. The first workshop was held in October 2007, Reno, NV to develop a formal work plan with all partners (Natural Resources Conservation Service, Agricultural Research Service, National Aeronautics and Space Agency, and University of Nevada at Reno). A second work shop was held in July 2008 in Tucson, AZ to review progress on meeting our milestones with all partners. In addition, we hold monthly teleconferences to review progress and make adjustments necessary to meet the original milestones of developing a prototype database to support the assessment of environmental benefits of conservation practices. We have completed testing of the Almanac model for predicting annual plant growth for Wyoming sagebrush plant communities and have developed methods to extract model parameters from NRCS Ecological Site Descriptions. We have completed initial testing of the Rangeland Hydrology Erosion Model using data from the NRCS National Resources Inventory database. We are currently evaluating approaches of extracting critical results from these two models for inclusion into the Hydrologic Unit Model of the United States database for use in developing parameterizes for the Soil Water Assessment Tool model and conducting regional assessments of environmental benefits of rangeland conservation practices within the Great Basin. Manuscripts are under development to describe the modeling approaches and the accuracy and precision of our current predictive capabilities. The manuscripts will be submitted for publication in FY 2009. The status of this project was monitored by the ADODR through telephone conversations, site visits and internet communications. This work supports National Program 215.