title: Pairing high-frequency data with a link-node model to manage dissolved oxygen impairment in a dredged estuary.
abstract: High-frequency data and a link-node model were used to investigate the relative importance of mass loads of oxygen-demanding substances and channel geometry on recurrent low dissolved oxygen (DO) in the San Joaquin River Estuary in California. The model was calibrated using 6 years of data. The calibrated model was then used to determine the significance of the following factors on low DO: excavation of the river to allow navigation of large vessels, non-point source pollution from the agricultural watershed, effluent from a wastewater treatment plant, and non-point source pollution from an urban area. An alternative metric for low DO, excess net oxygen demand (ENOD), was applied to better characterize DO impairment. Model results indicate that the dredged ship channel had the most significant effect on DO (62 % fewer predicted hourly DO violations), followed by mass load inputs from the watershed (52 % fewer predicted hourly DO violations). Model results suggest that elimination of any one factor will not completely resolve DO impairment and that continued use of supplemental aeration is warranted. Calculation of ENOD proved more informative than the sole use of DO. Application of the simple model allowed for interpretation of the extensive data collected. The current monitoring program could be enhanced by additional monitoring stations that would provide better volumetric estimates of low DO.
authors.affiliation: Ecological Engineering Research Program, School of Engineering and Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA. mcamarillo@pacific.edu.
authors.forename: Mary Kay
authors.identifier: http://orcid.org/0000-0002-9522-5127
authors.initials: MK
authors.lastname: Camarillo
authors.affiliation: Ecological Engineering Research Program, School of Engineering and Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Weissmann
authors.affiliation: Ecological Engineering Research Program, School of Engineering and Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA.
authors.forename: Shelly
authors.initials: S
authors.lastname: Gulati
authors.affiliation: Systech Water Resources, Inc., 1200 Mount Diablo Boulevard, Suite 102, Walnut Creek, CA, 94596, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Herr
authors.affiliation: Systech Water Resources, Inc., 1200 Mount Diablo Boulevard, Suite 102, Walnut Creek, CA, 94596, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Sheeder
authors.affiliation: Ecological Engineering Research Program, School of Engineering and Computer Science, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA.|Earth & Environmental Sciences Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Stringfellow
mesh_terms: D000383:Agriculture; D057919:Biological Oxygen Demand Analysis; D002140:California; D004784:Environmental Monitoring / Q000379:methods; D063366:Estuaries; D008962:Models, Theoretical; D010100:Oxygen / Q000032:analysis*; D045483:Rivers; D014865:Waste Disposal, Fluid
chemical_list: D010100:Oxygen
keywords: California; Dissolved oxygen; Estuary; Models; San Joaquin River; TMDL; Water quality