Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 7/20/2006
Publication Date: 8/1/2006
Citation: Mao, D., Cherkauer, K.A., Flanagan, D.C. 2006. Large-scale impacts of frozen soil on soil erosion: coupling the WEPP model to a macro-scale hydrologic model. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE). Paper No. 06-2188. p. 12. Interpretive Summary: Soil erosion occurs when the forces of wind or water move soil particles at very small spatial scales. Prediction equations and simulation models to estimate soil erosion by water have been developed over the past 50 years to be applied at the small field or farm scale. The Water Erosion Prediction Project (WEPP) is one such field/farm scale model. However, other types of hydrologic prediction models have been created and are used to understand how climate affects surface and subsurface water movement over much larger land areas. This type of simulation model can assist policymakers in determining the effects of geographic location, soils, climate, winter processes, vegetative cover, land-use, land management and other factors on water in the soil, plants, and atmosphere, and potentially managing future changes (urbanization, etc.) to maintain sustainable water quantity. This paper describes preliminary work on linking a large-scale hydrologic model with water erosion calculations from a small-scale erosion model. Ultimately this would provide information at larger spatial scales on the effects of various land management scenarios or land-use changes on the impacts on soil and water resources. This research potentially impacts other scientists, agency personnel, policymakers, and others responsible for evaluating or managing natural resources. Successful integration of WEPP with the Variable Infiltration Capacity (VIC) model would provide an additional tool to assist with assessment and protection of our soil and water resources.
Technical Abstract: Assessing environmental impacts of soil loss at large scales is necessary for regional management of natural resources and policy making. The process-based Water Erosion Prediction Project (WEPP) model has the ability to predict the spatial and temporal distribution of soil loss at a field scale. Recent development of a stand-alone version of the WEPP erosion code provides the basis for coupling with the Variable Infiltration Capacity (VIC) macro-scale hydrology model to predict long-term hillslope erosion potentials for large regions. This paper describes the coupling schematic and preliminary tests of coupled soil erosion predictions. Coupled model projections have similar estimation of annual average soil loss versus simulations using the full WEPP model for sampled hillslopes. Differences in soil loss estimation may be due to climate data discrepancies and uncertainties in scaling. The preliminary coupling study has highlighted a number of issues with the coupling process that still need to be addressed including problems with temporal and spatial scaling.