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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #328344
Research Project: Design and Implementation of Monitoring and Modeling Methods to Evaluate Microbial Quality of Surface Water Sources Used for Irrigation

Location: Environmental Microbial & Food Safety Laboratory

Title: Bacteria transport simulation using apex model in the toenepi watershed, New Zealand

Author
item HONG, EUNMI - Orise Fellow
item Pachepsky, Yakov
item PARK, YONG EUN - Us Forest Service (FS)
item MUIRHEAD, RICHARD - Agresearch
item Shelton, Daniel

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2016
Publication Date: 4/27/2016
Citation: Hong, E., Pachepsky, Y.A., Park, Y., Muirhead, R., Shelton, D.R. 2016. Bacteria transport simulation using apex model in the toenepi watershed, New Zealand. BARC Poster Day. 27th Annual Beltsville Poster Day, National Agriculture Library, April 27, 2016..

Interpretive Summary:

Technical Abstract: The Agricultural Policy/Environmental eXtender (APEX) model is a distributed, continuous, daily-timestep small watershed-scale hydrologic and water quality model. In this study, the newly developed fecal-derived bacteria fate and transport subroutine was applied and validated using APEX model. The expermental study was conducted in the Toenepi watershed located in the Waikato region of the North Island, New Zealand. The prominent land use is intensive pasture-based dairy, and typically 40 kg of animal waste/animal/day is applied directly onto the land as the cows graze. Sensitivity analysis was conducted using the FAST (Fourier amplitude sensitivity testing) method. The return flow ratio, groundwater residence day, groundwater storage threshold and CN index coefficient were sensitive parameters for stream flow simulation. Stream flow was calibrated with the data from watershed outlet. The accuracy of the model was classified as good. The model performance with regard to E. coli was most sensitive to the intial copncentrations of this organism in manure. The average New Zealand value of 2.4 × 10 6 (1.7 × 10 3 - 4.9 × 10 6) MPN/g provided the the best results. This study will contribute to evluation of best management ractices related to grazing at the Toenepi watershed. However, further development of the in-stream bacteria fate and transport model appears to be needed to improve simulations of E. coli concentrations.