Divergence Between Long‐Term and Event‐Scale Nitrate Export Patterns

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(10)

Published: May 23, 2024

Abstract The mechanisms driving catchment nitrogen storage and release operate at multiple spatiotemporal scales. Consequently, analyses grounded in different observational timescales can yield discrepant interpretations of underlying mechanisms. To assess the consistency nitrate export patterns between event‐ inter‐annual scales, we evaluated years high‐frequency observations concentrations (C) discharge (Q) including 3,480 discrete events from 28 dominantly agricultural catchments. We observed consistent often drastic divergence long‐term median event‐specific C‐Q patterns. Most catchments showed enrichment (positive slope), but were, on average, more chemostatic (close‐to‐zero slopes). slope variability was high for small decreased with event magnitude, approaching during largest storms, yielding compelling evidence against source limitation. conclude that temporal scales magnitudes are controlled by processes, therefore embedding complementary information.

Language: Английский

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Solute export patterns across the contiguous USA

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(6)

Published: June 1, 2024

Abstract Understanding controls on solute export to streams is challenging because heterogeneous catchments can respond uniquely drivers of environmental change. To understand general patterns, we used a large‐scale inductive approach evaluate concentration–discharge (C–Q) metrics across spanning broad range catchment attributes and hydroclimatic drivers. We leveraged paired C–Q data for 11 solutes from CAMELS‐Chem, database built upon an existing dataset relatively undisturbed the contiguous USA. Because relationships with Q thresholds reflect shift in dynamics are poorly characterized diverse catchments, analysed using Bayesian segmented regression quantify relationship. Threshold responses were rare, representing only 12% relationships, 56% which occurred predominantly sourced bedrock. Further, dominated by one or two patterns that reflected vertical solute–source distributions. Specifically, bedrock had diluting 43%–70% soils more enrichment 35%–51% catchments. also linked patterns. The generally weak despite diversity attribute types considered. However, central USA typically drove most divergent behaviour solutes. illustrate how our generated new hypotheses be tested at discrete, representative deductive approaches better processes underlying Finally, given these long‐term minimally disturbed findings as benchmarks change

Language: Английский

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Monitoring water quality in the lower Kansas River using remote sensing

River, Journal Year: 2024, Volume and Issue: 3(3), P. 284 - 303

Published: Aug. 1, 2024

Abstract We demonstrate how to combine remote sensing data from satellite imagery (Sentinel‐2) with in situ water quality gauging (USGS Super Gages and the Gybe hyperspectral radiometer) create spatially dense maps of parameters (chlorophyll‐a concentration, turbidity, nitrate plus nitrite concentration) along lower Kansas River. The are created using locally tuned models target parameters, this study describes steps used design, calibrate, validate empirical correlations. Water such as chlorophyll‐a concentration correlated well‐studied absorption scattering features visible spectrum (roughly 400–700 nm). Nutrients (such lack strong spectrum, those cases we describe a novel surrogate modeling approach that identifies overlapping parcels between imagery. Measurements yield excellent correlations () for limited windows time (or sections river reaches). Examples provided illustrating can be track inputs ungauged sources creeks), or reveal mixing patterns at confluences.

Language: Английский

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Antimony Flux and Transport Dynamics in a Mining‐Impacted River Is Linked to Catchment Hydrodynamics and Climate Oscillations

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(11)

Published: Nov. 1, 2024

ABSTRACT We investigate how seasonal flow variations and a climatic regime that is dominated by the El Niño–Southern Oscillation (ENSO) influence Sb flux dynamics in an Australian river impacted mining. Sampling ( n = 496) spans hydrologically complex 7‐year period of drought, bushfires floods from 2016 to 2023, during which 17% samples exceeded drinking water guideline concentration (3 μg L −1 ). Aqueous (Sb Aq ) concentration–discharge C – Q relationships are non‐continuous/non‐linear across range, with chemodynamic behaviour at moderate flows reflecting hydrological connection primary Sb‐source area combined variable dilution. In contrast chemostatic occurred extreme low high flows, disconnection source persistent dilution, respectively. was significantly positively correlated p < 0.01, Spearman's ρ 0.58) index representing proportional contribution sub‐catchment mineral‐field area, suggesting sufficient localised rainfall mining‐impacted contributes downstream peaks concentrations. particulate P annual loads study spanned 24–5174 1.2–2820 kg, respectively were strongly dependant interannual variability dry wet years. extrapolate daily load‐daily discharge d for estimate over 53‐year (1970–2023) continuous data (mean total 1865 kg ± [SE] 247). Positive correlations between Southern Index both 0.05) 53 years suggests ENSO fluctuations transport dynamics. Upstream load estimates correspond coastal floodplain sedimentary mass, approximately 10%–45% estimated exported since 1880 accumulated on Macleay floodplain. Data suggest current rates export, complete flushing‐leaching mine tailings‐derived upper catchment may take order 600–1000

Language: Английский

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Concentration‐Discharge Relationships Revisited: Overused But Underutilised?

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(11)

Published: Nov. 1, 2024

ABSTRACT Over the past 50 years, concentration‐discharge (cQ) relationships have been widely used to analyse water quality dynamics. Nowadays improved availability of concentration ( c ) and discharge Q data at different spatial temporal scales led a high popularity cQ applications. However, despite their widespread use, we see persistent challenges in integration across scales, identification encoded processes. In this commentary, show that catchment processes may lead similar responses resulting lack clear causality. We emphasise applied time integrate parts may, therefore, convey information. Finally, advocate for careful use relationship as one, but not only, tool addressing ecohydrological questions.

Language: Английский

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Flow-weighted sourcing of freshwater runoff from Pacific-draining continental and coastal basins in south-western Patagonia (41-56° S): characterizing regional inputs to Chilean fjords

Frontiers in Marine Science, Journal Year: 2024, Volume and Issue: 11

Published: Sept. 19, 2024

Global estimates of the supply dissolved and suspended materials to ocean, in order be relevant at either political or ecological scales, belie a finer-scale analysis necessary for understanding specific terrestrial-marine interactions. This is especially true continental runoff marine critical zone inland fjords channels, where mechanisms, drivers, predictions need elaborated context changing land use shifting climate forcing. In south-western Patagonia, from small coastal large basins (~310 x10 3 km 2 ), sourced diverse geography wide climatic gradient (&lt;150 – 6,000+ mm/year), correspond with very low density hydrological water quality observations. Based on recently developed regional model (FLOW), we estimated freshwater discharges characterized flow-weighted sourcing (land use-cover type, climate, glaciers/geology, soil province) Pacific drainages 41° 56° south latitude. An 692 /year (mean across 1979-2018), 2% worldwide total, more than 85% previous much larger South American input. limited observations inference sourcing, predict general patterns export four groups resources important productivity, including: significant variation flow seasonality, N-S declining input silicic acid increased glacial sediment iron, potential shift organic matter sources rainforest (potentially labile) peatlands (refractory). Finally, emphasize temporal spatial consequences near-reference condition river ecosystem productivity function Patagonian fjords, recommendations standards sustained monitoring coupled ecosystems.

Language: Английский

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Microbial community storm dynamics signal sources of “old” stream water

PLoS ONE, Journal Year: 2024, Volume and Issue: 19(9), P. e0306896 - e0306896

Published: Sept. 24, 2024

Accurate characterization of the movement water through catchments, particularly during precipitation event response, is critical for hydrological efforts such as contaminant transport modeling or prediction extreme flows. Abiotic hydrogeochemical tracers are commonly used to track sources and ages surface waters but provide limited details about transit pathways spatial dynamics storage release. Alternatively, biotic material in streams derived from thousands taxa originating a variety environments within watersheds, including groundwater, sediment, upslope terrestrial environments, this can be characterized with genetic sequencing bioinformatics. We analyzed stable isotopes (δ 18 O δ 2 H) microbiome composition (16S rRNA gene amplicon sequencing) Marys River western Oregon, USA an early season storm describe processes, storage, flowpaths that shape hydrology. Stable typified response which stream composed largely ‘old’ introduced catchment before storm, common though not well understood phenomenon. In contrast, microbial biodiversity spiked consisting early- late-event communities clearly distinguishable pre-event communities. applied concentration-discharge (cQ) analysis individual found most Alphaproteobacteria sequences were positively correlated (i.e., mobilized) discharge, whereas phyla Gammaproteobacteria Bacteroidota negatively discharge diluted). Source predictions using prokaryote habitat preference database ProkAtlas freshwater-associated microbes smaller fraction community rise larger recession, while soil biofilm-associated increased remained high recession. This suggests “old” discharged was likely stored released from, passed through, soil- biofilm-rich demonstrating approach adds new, biologically tracer information hydrologic active after event. Overall, study demonstrates integrating information-rich DNA into resource investigations, incorporating tools both hydrology microbiology demonstrate useful only indicator also functions innovative tracer.

Language: Английский

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Surface Water Chemistry as an Integrated Signal of Ecosystem Vectors and Critical Zone Reactors

Published: Jan. 1, 2024

Language: Английский

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A Review of Suspended Sediment Hysteresis

Water Resources Research, Journal Year: 2024, Volume and Issue: 61(1)

Published: Dec. 31, 2024

Abstract The study of sediment‐riverflow interactions during discrete hydrological events is vital for enhancing our understanding the cycle. Hysteresis analysis, relying on high‐resolution, continuous monitoring suspended sediment concentration (SSC) and discharge (Q) data, an effective tool investigating complex events. It captures differing dynamic at same level, which results from asynchrony between hydrograph graph different phases event. However, there has been no comprehensive review systematically addressing utility significance hysteresis analysis in soil water management. This synthesizes findings over 500 global studies, providing a detailed examination current research. We trace development application hydrology, illustrating its role classifying characterizing events, as well uncovering sources transport mechanisms. Furthermore, proven identifying critical offering valuable insights targeted watershed Our spatiotemporal research shows that 70% studies are located semi‐arid Mediterranean climate zones, with increasing focus alpine tropical regions due to change. also highlights limitations, including scarcity high‐resolution inconsistent use quantitative indices, limited integration patterns into predictive approaches. Future should developing region‐specific models incorporate dynamics, along standardizing methodologies apply across diverse climatic geomorphic settings.

Language: Английский

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