Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Research Notes
Publication Acceptance Date: 6/1/1994
Publication Date: N/A
Interpretive Summary: The USDA-Water Erosion Prediction Project (WEPP) computer model is being developed to improve the management of forest, range, and agricultural lands. To function effectively, the WEPP model and its components need extensive testing and validation. The Water balance submodel component of WEPP was tested on two rangeland sites on the Reynolds Creek Experimental Watershed in southwestern Idaho. The results of this research showed that this version of the water balance submodel of WEPP can function effectively on rangeland watersheds, and it provided insight for continued development and improvement.
Technical Abstract: Simulation of the root zone soil water balance is an important part of the USDA-Water Erosion Prediction Project (WEPP) computer model because: 1) soil water affects the subsequent rainfall/runoff events, 2) root zone soil water content is used in the interaction between soil water and plant growth, and 3) soil water content is used in residue decomposition. In the WEPP computer model, simulation of the infiltration precess is linked with soil water redistribution, soil evaporation, plant transpiration, subsurface lateral flow, and subsurface drainage to calculate daily root zone water content. Hydrometerological data from two sites with different climate, soil and vegetal cover were used to evaluate the WEPP-water balance submodel. In general, the WEPP water balance submodel simulated evapotransporation and root zone soil water content with acceptable accuracy.