Submitted to: ASAE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: January 23, 2003
Publication Date: July 27, 2003
Citation: Pachepsky, Y.A. 2003. Modeling manure-borne pathogen transport with runoff and infiltration. ASAE Annual International Meeting. p.47. Technical Abstract: The kinematic wave model for the overland flow was coupled with one-dimensional modules for vertical water and solute transport into new model STIR (Solute Transport with Infiltration and Runoff) to simulate surface and subsurface transport of manure-borne pathogens. Finite difference and finite element methods were used to solve transport equations of overland and subsurface flow, respectively. The solution was iterative, so that the subsurface modules provided infiltration flux values for the overland module, and the overland flow module provided the surface pressure head as a boundary condition for the subsurface module. The model STIR was tested with data on fecal coliform and bromide transport on a grassed and bare plot 6-m long with 20% slopes where manure was applied in a 30-cm strip on the top 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. The exponential model of the release of bromide and fecal coliforms from manure provided the satisfactory approximation. 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.