Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/15/2003
Publication Date: 7/27/2003
Citation: Pachepsky, Y.A., Shelton, D.R., Guber, A., Sadeghi, A.M. 2003.Modeling surface and subsurface transport of manure-borne pathogens. Soil and Water Conservation Society Proceedings, July 25-30, 2003, Spokane, WA. p.56 Interpretive Summary:
Technical Abstract: Manure-borne pathogens partition between overland flow and infiltration when dissolved manure enters runoff. The objective of this work was to develop and test the first simple model of such partitioning to see what additional complexity and observations may be needed to capture essential processes in the model. The kinematic wave model for the overland flow was coupled with one-dimensional modules for vertical water and solute transport from the SWMS models into new model STIR (Solute Transport with Infiltration and Runoff). Finite difference and finite element methods were used to iteratively solve transport equations of overland and subsurface flow, respectively. The model STIR was tested with data on fecal coliform and bromide transport on vegetated and bare plots located in Beltsville research center. Manure was applied in a 30-cm strip on the top of 6-m long slopes and rainfall was simulated for 1-2 hours. Accounting for time-dependent surface crusting was needed to simulate water transport at bare plots. Both fecal coliforms and bromide were leached into soil mostly in the vicinity of the manure strip at grassed plot while soil was approaching saturation. Only low concentrations of fecal coliforms and bromide were available for surface transport when the runoff was initiated. Simulations of subsurface concentrations showed a delay indicating possible need in two-dimensional description of subsurface flow. The model STIR is a prototype of pathogen transport sub-module that needs to be added to existing erosion/runoff models to access the efficiency of vegetated filter strips in preventing pathogens from entering surface water.