|Yakirevich, Alex -|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2010
Publication Date: November 14, 2010
Citation: Guber, A.K., Pachepsky, Y.A., Yakirevich, A., Shelton, D.R., Sadeghi, A.M., Rowland, R.A., Goodrich, D.C., Unkrich, C.L. 2010. Module STWIR for KINEROS-based Simulations of the Field-scale Manure-Borne Bacteria Transport with Runoff. Meeting Abstract. ASABE Pub No. 711p0710cd. Technical Abstract: Evaluation of manure application effects on bacteria concentrations in streams and ponds adjacent to fields benefits from microbial transport models. The objectives of this work were: (i) to develop and calibrate an event-based model describing manure-borne bacteria transport with runoff water at a field scale; and (ii) to characterize the propagation in initial bacteria distributions to the model predictions. A bacteria transport add-on module STWIR was developed for the event-based kinematic runoff model KINEROS2. The module describes convective-dispersive overland transport and accounts for bacteria release from manure, reversible attachment-detachment to soil, and surface straining of infiltrating bacteria Experimental data to calibrate and test the module were obtained at the ARS Beltsville watershed site (OPE3) in Maryland. Bovine manure at the rate of 60 ton/ha application rate was applied on the 3.6 hectare experimental field. Water content and fecal coliform (FC) contents were measured in the upper 10-cm soil layer before and after manure applications. Both runoff volume and FC concentrations in runoff water were monitored using flume equipped with a refrigerated sampler during 6 consecutive runoff events. Fecal coliform concentrations were highest in the runoff water collected 7 days after the manure application and then declined with time. The model was successfully calibrated with the field experiment data. Monte Carlo simulations that accounted for the spatial variation in FC in applied manure were run to assess the uncertainty in the model predictions. The simulations indicated that high spatial variation of bacteria concentrations in manure and the limited information on the magnitude of this variation were major sources of uncertainty in predictions of bacteria transport.