Submitted to: Earth Surface Processes and Landforms
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/23/2006
Publication Date: 8/1/2007
Citation: Bulygina, N.S., Nearing, M.A., Stone, J.J., Nichols, M.H. 2007. Dwepp: a dynamic soil erosion model based on wepp source terms. Earth Surface Processes and Landforms. 32:998-1012. Interpretive Summary: Regulatory policy and land management approaches include the use of soil erosion assessment tools to provide the information on natural hazards and human impacts to support soil conservation planning, both through agricultural legislation that defines maximum tolerable soil loss rates, and through federal and local legislation that requires soil erosion controls on many construction sites. To be useful for decision makers, soil erosion models must have simple data requirements and must be applicable to a variety of regions with minimum calibration. We have two models, KINEROS2 and WEPP, which each have their distinct advantages and disadvantages. The intention of this research was to create a model that is easy to use, can be parameterized given basic field data, can well represent the effects of management practices on erosion, and is based on best available process representations. Thus we decided to unite the advantageous features of both models: to have KINEROS2 as a base and to insert a WEPP-like dynamic erosion module instead of its former steady-state version. The impact of this research will be more accurate representations and understanding of the effects of land management on soil erosion and sediment yields when making predictions with USDA hydrologic assessment tools such as AGWA.
Technical Abstract: A soil erosion model for rangelands with simple data requirements and wide range of applicability without calibration is needed. A new rangeland overland-flow erosion model was developed based on KINEROS2 (KINematic EROSion 2) hydrology and a dynamic erosion equation with WEPP (Water Erosion Prediction Project)-like source/sink terms. Model response was tested for steady state conditions so that the output could be compared with that given by WEPP. Then total sediment yield was estimated for rainfall simulation plots from the WEPP field experiments. Results for the two models were very similar. Also, soil loss dynamics was plotted and compared with experimental results for plots. Lastly, the model was tested on a small watershed that did not have a well-developed channel network. The outputs for plot and hillslope scale simulations were in the range of possible natural variability, which implies that the validation was successful. The new model provides information on erosion rates and dynamics, has the best available erosion mechanics descriptions, is sensitive to treatment