Seasonally varying contributions of contemporaneous and lagged sources of instream total nitrogen and phosphorus load across the Illinois River basin.

Autor: Schmadel NM; U.S. Geological Survey, Portland, OR, USA. Electronic address: nschmadel@usgs.gov., Miller OL; U.S. Geological Survey, Salt Lake City, UT, USA., Ator SW; U.S. Geological Survey, Baltimore, MD, USA., Miller MP; U.S. Geological Survey, Boulder, CO, USA., Schwarz GE; U.S. Geological Survey, Reston, VA, USA., Robertson DM; U.S. Geological Survey, Madison, WI, USA., Sekellick AJ; U.S. Geological Survey, Baltimore, MD, USA., Skinner KD; U.S. Geological Survey, Boise, ID, USA., Saad DA; U.S. Geological Survey, Madison, WI, USA.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Dec 10; Vol. 955, pp. 176816. Date of Electronic Publication: 2024 Oct 11.
DOI: 10.1016/j.scitotenv.2024.176816
Abstrakt: Quantifying nutrient sources in streams, their temporal and spatial variability, and drivers of that variability can support effective water resources management. Yet a lack of data and modeling capabilities has previously prevented comprehensive quantification across both space and time. Here a dynamic SPARROW (Spatially Referenced Regressions on Watershed attributes) model that accounts for a lagged delivery of nutrients to streams was developed and applied to simulate seasonal and source-specific total nitrogen (TN) and total phosphorus (TP) loads in streams across the Illinois River basin (IRB). Dynamic load predictions from 2000 through 2020 revealed that a third of the TN and a quarter of the TP instream load originated from non-point sources that were lagged in their delivery from land-application to streams by more than a season. This lagged mass was the largest overall TN source-which was estimated as a lagged expression of previous seasonal non-point sources including fertilizer, manure, atmospheric deposition and fixation, and urban land use. Treated wastewater effluent was the largest TP source exported from the basin, contributing 39 % of the TP load and 15 % of the TN load, and dominated the load in the upper Illinois River near Chicago. Loads in the lower river during this period, conversely, were attributed primarily to a mix of agricultural sources and their lagged fractions from headwater tributaries. Instream processes removed 10 % of the TN load while only 4 % of the TP load was removed during instream transport. With appropriate datasets, the models could be extended to other basins or time periods and used to forecast future seasonal nutrient loads.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Published by Elsevier B.V.)
Databáze: MEDLINE
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