|COSTIGAN, KATIE - UNIVERSITY OF NEVADA|
|SAITO, LAUREL - UNIVERSITY OF NEVADA|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2008
Publication Date: 2/3/2009
Citation: Costigan, K., Weltz, M.A., Saito, L. 2009. Estimating Conservation Thresholds on Rangelands [abstract]. Water Resource Association Annual Conference.
Technical Abstract: The Conservation Effects Assessment Project (CEAP) is a multi-agency effort designed to quantify the environmental and economic impacts of land conservation practices. One of USDA’s goals is to identify Conservation Thresholds, the point at which accelerated erosion occurs, and to examine the usefulness of the Rangeland Hydrology and Erosion Model (RHEM) in determining the Conservation Threshold. Soil erosion is heavily influenced by a number of factors including the percent of ground cover and precipitation intensity and duration. Theoretically, there is a threshold of cover below which soil erosion is initiated and rills begin to form. This is the minimum amount of ground cover that a landowner should maintain to reduce the impacts of erosion. Another threshold is the amount of cover at which there is minimal soil erosion and it becomes economically unnecessary for the landowner to increase cover because it will have little impact on reducing soil erosion. Using the Rangeland Hydrology and Erosion Model (RHEM), the location of these thresholds will be examined by modeling different scenarios of ground cover and storm intensity. The model will be calibrated in the laboratory using a rainfall simulator for 2, 5, 10, 25, 50 and 100 year, 60 minute return period storms on a plot that is 1.2 by 2.4 m in size. Sediment yield and percent cover will be measured and compared to the predictions of the RHEM model. These results will be used to provide guidance to land managers for implementation of land conservation practices to minimize soil erosion.