Sources of dissolved carbon in large rivers: Insights from coupled 13C-14C in the upper Changjiang (Yangtze) River

Earth and Planetary Science Letters, Journal Year: 2024, Volume and Issue: 642, P. 118813 - 118813

Published: June 27, 2024

Language: Английский

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Quantification of Carbopeaking and CO2 ${\text{CO}}_{2}$ Fluxes in a Regulated Alpine River

Water Resources Research, Journal Year: 2025, Volume and Issue: 61(2)

Published: Feb. 1, 2025

Abstract Carbon dioxide () fluxes in regulated Alpine rivers are driven by multiple biogeochemical and anthropogenic processes, acting on different spatiotemporal scales. We quantified the relative importance of these drivers their effects dynamics concentration atmospheric exchange a representative river segment cascading hydropower system with diversion, which includes two residual flow reaches reach subject to hydropeaking. combined instantaneous time‐resolved water chemistry hydraulic measurements at times year, main calibrating one‐dimensional transport‐reaction model measured data. As novelty compared previous inverse modeling applications, also included carbonate buffering, contributed significantly budget case study. The distribution depended operations. Along reaches, were directly affected upstream dams only first 2.5 km, where supply supersaturated from reservoirs was predominant. Downstream diversion outlets, dominated systematic sub‐daily fluctuations transport evasion (“carbopeaking”) Hydropower operational patterns regulation approaches affect response across temporal Our findings highlight considering all scales variations for accurate quantification understanding impacts, clarify role natural global carbon cycling.

Language: Английский

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Long-term trends of streamwater chemistry in an agricultural watershed: Effects of anthropogenic and climatic factors

The Science of The Total Environment, Journal Year: 2025, Volume and Issue: 970, P. 179017 - 179017

Published: March 1, 2025

Language: Английский

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Reactive transport simulation of organic and inorganic carbon cycling following carbon dioxide sorption onto soil amendments in drylands

Frontiers in Climate, Journal Year: 2025, Volume and Issue: 7

Published: March 7, 2025

Terrestrial nature-based climate solutions (NbCS) for carbon dioxide removal (CDR) are critical mitigating change. However, the arid climates characteristic of drylands (aridity index <0.65) often limit effectiveness many NbCS. At same time, cover approximately 45% global land area and threatened by soil degradation, necessitating deployment CDR methods that also promote health. Soil amendments with high CO 2 sorption capacity, such as biochar, could provide potential health benefits in provided they do not negatively impact large inorganic pools typical dryland soils. The dynamics therefore assessing response systems to sorbing amendments. To assess sorption, we developed a 1D reactive transport model unsaturated soils equilibrium dissolved calcite under varying respiration rates amendment application conditions. simulations highlight how alteration due biochar affects carbon, pH, Ca 2+ , calcite. transient conditions emerge, including delayed emissions respired emphasize need consider times monitoring campaigns based on measurements. In scenarios where is low, drylands, becomes increasingly important. Although variable was modest relative overall deployment, impacts altered gas important developed.

Language: Английский

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Divergent Effects of Agriculture on River Methane and Carbon Dioxide Concentrations and Emissions: Insights from Multiple Techniques

ACS ES&T Water, Journal Year: 2025, Volume and Issue: unknown

Published: March 24, 2025

This study examined the impacts of agriculture on methane (CH4) and carbon dioxide (CO2) dynamics in an agricultural river eastern China. The dissolved CH4 concentrations (dCH4; 422 ± 188 nmol L–1 summer 193 190 winter) emissions (6430 11,650 μmol m–2 d–1 396 1190 were closely associated with agriculture-enhanced allochthonous inputs methanogenesis by methanogens algae. shallow water depth low flow velocity plain favorable for bubble release. pressure CO2 (pCO2) values substantially higher than atmospheric level, emission rates 96 159 mmol 27 64 winter. pCO2 largely regulated pH, which was not particularly relevant to activities. Notably, methanotrophs contributed significantly Therefore, could generate more fluvial CO2, is crucial understanding anthropogenic simulation budgets global biogeochemical models.

Language: Английский

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Sources and fate of CO2 along the soil–aquifer–stream–atmosphere continuum (the Orgeval headwater catchment, France)

Geoderma, Journal Year: 2025, Volume and Issue: 458, P. 117297 - 117297

Published: April 25, 2025

Language: Английский

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Unexpected contributions by carbonates and organic matter in a silicate-dominated tropical catchment: An isotope approach

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 948, P. 174651 - 174651

Published: July 9, 2024

The understanding of global carbon has rarely extended to small-scale tropical river basins. To address these uncertainties, this study aims investigate the importance rock weathering and organic matter turnover in cycle a terrain dominated by crystalline silicate rocks. geochemical composition dissolved particulate phases (DIC, DOC POC) their stable isotopes were studied Deduru Oya River Sri Lanka. Dissolved inorganic (DIC) was most dominant phase its contribution total pool varied between 67 89 %. Furthermore, δ13CDIC values −1.1 −16.5 ‰. lithological characteristics molar ratios Ca2+, Mg2+ HCO3− indicated mainly CO2 carbonic acid. for groundwater input −15.9 ‰, while carbonate weathering, due fertiliser input, they reached value −12.7 This fed into an isotope mass balance determine relative contributions. However, only plausible after correcting effects on caused degassing photosynthesis. Our demonstrated that are essential components even catchment. They can represent up 60 % DIC pool. Combined with higher high pCO2 water, it be suggested acts as net source atmosphere. shows in-stream photosynthesis systems need considered along chemical account transport rivers.

Language: Английский

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Toward Modeling Continental‐Scale Inland Water Carbon Dioxide Emissions

AGU Advances, Journal Year: 2024, Volume and Issue: 5(6)

Published: Nov. 4, 2024

Abstract Inland waters emit significant amounts of carbon dioxide (CO 2 ) to the atmosphere; however, global magnitude and source distribution inland water CO emissions remain uncertain. These fluxes have previously been “statistically upscaled” by independently estimating dissolved concentrations gas exchange velocities calculate fluxes. This scaling, while robust defensible, has known limitations in representing spatial variability. Here, we develop calibrate a transport model for continental United States, simulating transformation >22 million hydraulically connected rivers, lakes, reservoirs. We estimate 25% lower compared upscaling estimates forced same observational calibration data. While precise are limited resolution parameterizations, our suggests that stream corridor production dominates over groundwater inputs at scale. Our results further suggest lack networks scalable metabolic models aquatic most salient barriers coupling with other Earth system components.

Language: Английский

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Different Effects of Agriculture on River Methane and Carbon Dioxide Concentrations and Emissions: Insights from Multiple Techniques

Published: Jan. 1, 2024

Language: Английский

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Predominant biogenic contribution of dissolved inorganic carbon in karst rivers, Southwest China

Chemical Geology, Journal Year: 2024, Volume and Issue: unknown, P. 122404 - 122404

Published: Sept. 1, 2024

Language: Английский

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