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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Modeling Soil Erosion and Sediment Yield in Rangeland Environments

Location: Southwest Watershed Research

2010 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. Documents SCA with U of AZ. Replacing 5342-12660-004-02S 407119 (3/08).

3. Progress Report
This project involves using digital imagery, image processing software, and spatial analysis to quantify the spatial distribution of rangeland vegetation. These data were used with runoff and erosion data taken at the same sites to develop relationships between vegetation spatial characteristics and hydrologic and erosion processes. Imagery and hydrologic data have been taken at more than 10 rangeland sites with vegetation that includes predominately grass species, shrub species, and mixed grass and shrub species. All of the images were classified using image processing software and used to compute a variety of spatial metrics. The results were that one metric, a ratio of the largest patch area to total patch area of a class (i.e. canopy or intercanopy) was related to both the ecological condition of the site as classified by the site's state and transition model and the plot sediment yield. Because this metric is based on projected cover, these results suggest that this metric may be able to be estimated using remote sensing at a larger than plot scales. NP 211, Problem Area 4 - Integrated Soil Erosion and Sedimentation Technologies, Product 2 – Sediment Yield Data Bases. ADODR Monitoring Activities: ADODR meets with and speaks with University of Arizona employees on a weekly to daily basis to ensure that the project goals are being met.

4. Accomplishments

Last Modified: 08/17/2017
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