2012 Annual Report 1a.Objectives (from AD-416): The objectives of this cooperative research project are to develop new methods and technologies to improve the measurement and modeling of erosion and sediment yield at a range of scales, with an emphasis on the development of the Rangeland Hydrology and Erosion Model (RHEM) and application to the Conservation Effects Assessment Project (CEAP). Develop methods and techniques for quantifying natural and anthropogenic induced ephemeral-channel runoff and subsequent recharge in cooperation with U.S. Geological Survey Tucson Science Center under current and projected climate scenarios Develop methods and techniques to quantify and predict water budgets of riparian ecosystems under current and projected climate scenarios through direct measurements of evaporation and plant transpiration and predict water savings by removal of invasive mesquite vegetation. Develop methods and techniques to explicitly quantify the spatial and temporal distribution of vegetation, land use, and infiltration reduction using remotely sensed methods to improve prediction of basin scale semi-arid water budget components. 1b.Approach (from AD-416): The RHEM model will be tested, and parameter estimation procedures will be developed. A web-based interface will be constructed. The model will be linked to NRCS databases included the National Resource Inventory (NRI), and methods will be developed to assess the impact of conservation practices on natural resources, and soil erosion in particular. Relative accuracy of the models will be compared and documented, and models will be evaluated in terms of the type of information that each model is able to provide. 3.Progress Report: The RHEM model was tested, and parameter estimation procedures were developed. A web-based interface was constructed. The model was linked to NRCS databases included the National Resource Inventory (NRI), and methods were developed to assess the impact of conservation practices on natural resources, and soil erosion in particular. Relative accuracy of the models were compared and documented, and models were evaluated in terms of the type of information that each model is able to provide. This project contributes to parent project Objective 2: Develop decision tools including a rangeland specific hydrology and erosion model for improved planning and evaluation of rangeland management practices.