Sampling frequency, load estimation and the disproportionate effect of storms on solute mass flux in rivers.

Autor: Wang J; University of Illinois at Urbana-Champaign, Department of Earth Science and Environmental Change, Urbana, IL, USA., Bouchez J; Institut de Physique du Globe de Paris, Paris, France., Dolant A; University of Illinois at Urbana-Champaign, Department of Civil and Environmental Engineering, Urbana, IL, USA; Extralab Company, Orsay, France., Floury P; Extralab Company, Orsay, France., Stumpf AJ; University of Illinois at Urbana-Champaign, Illinois State Geological Survey, Champaign, IL, USA., Bauer E; University of Illinois at Urbana-Champaign, Illinois State Water Survey, Champaign, IL, USA; University of Illinois at Urbana-Champaign, Prairie Research Institute, Champaign, IL, USA., Keefer L; University of Illinois at Urbana-Champaign, Illinois State Water Survey, Champaign, IL, USA., Gaillardet J; Institut de Physique du Globe de Paris, Paris, France., Kumar P; University of Illinois at Urbana-Champaign, Department of Civil and Environmental Engineering, Urbana, IL, USA; University of Illinois at Urbana-Champaign, Prairie Research Institute, Champaign, IL, USA., Druhan JL; University of Illinois at Urbana-Champaign, Department of Earth Science and Environmental Change, Urbana, IL, USA; Institut de Physique du Globe de Paris, Paris, France. Electronic address: jdruhan@illinois.edu.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Jan 01; Vol. 906, pp. 167379. Date of Electronic Publication: 2023 Sep 28.
DOI: 10.1016/j.scitotenv.2023.167379
Abstrakt: Riverine discharge (Q) and dissolved concentrations (C) dictate solute mass export from watersheds. Commonly Q is tracked at a much higher frequency than C for most major solutes, leading to the necessity of load estimation algorithms which are often based on sparse data. The result is that the disproportionate effects of short-duration events (e.g., storms) on solute mass fluxes are poorly known. Here we use novel lab-in-the-field instrumentation to compare high temporal-resolution (∼30 min to 7 h) datasets of major ion chemistry collected over a year of continuous monitoring in three watersheds ranging over four orders of magnitude in drainage area. In these diverse settings, we quantify the errors associated with common load estimation algorithms and reduced sampling frequencies. When sample frequencies are coarsened, the mass flux of solutes which are diluted by storm events (i.e., Ca 2+ , Mg 2+ , Na + , Cl - and SO 4 2- ) are systematically overestimated, while nutrients which become mobilized by these events (K + and NO 3 - ) are underestimated. This is most pronounced in the largest river, and strongly tied to the increasing likelihood that storm events are missed as sampling frequencies decrease. Coarsening our high-resolution data to monthly sampling frequency yields an average overestimate of 8 % for Na + and an average underestimate of 32.5 % for K + across the three watersheds, illustrating clear implications for estuary and coastal water eutrophication, chemical weathering budgets, and agricultural land management practices. SYNOPSIS: A new 'lab-in-the-field' technology produces continuous high-frequency records of the full suite of major ions in rivers. These data highlight the disproportionate effect of large storms on catchment solute exports and the error associated with temporally coarse monitoring.
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.
(Copyright © 2023. Published by Elsevier B.V.)
Databáze: MEDLINE
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