Dynamics of dissolved organic carbon in hillslope discharge: Modeling and challenges

Dušek, Jaromír; Vogel, Tomáš; Dohnal, Michal; Barth, Johannes A. C.; Šanda, Martin; Marx, Anne; Jankovec, Jakub

doi:10.1016/j.jhydrol.2016.12.054

Cited by 22 publications

(18 citation statements)

References 90 publications

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“…The interplay of biological, chemical, and physical processes that influence CO 2 in headwater streams is complex and often causes high spatiotemporal variability [ Dawson et al , ; Hope et al , ; Peter et al , ; Wallin et al , ]. First models highlight the variability and outline that DOC transport and turnover often start in soils [ Dusek et al , ].…”

Section: Co2 Contents In Streamsmentioning

confidence: 99%

A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective

Marx

Dušek

Jankovec

et al. 2017

Reviews of Geophysics

270

216

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Terrestrial carbon export via inland aquatic systems is a key process in the global carbon cycle. It includes loss of carbon to the atmosphere via outgassing from rivers, lakes, or reservoirs and carbon fixation in the water column as well as in sediments. This review focuses on headwater streams that are important because their stream biogeochemistry directly reflects carbon input from soils and groundwaters. Major drivers of carbon dioxide partial pressures (pCO2) in streams and mechanisms of terrestrial dissolved inorganic, organic and particulate organic carbon (DIC, DOC, and POC) influxes are summarized in this work. Our analysis indicates that the global river average pCO2 of 3100 ppmV is more often exceeded by contributions from small streams when compared to rivers with larger catchments (> 500 km2). Because of their large proportion in global river networks (> 96% of the total number of streams), headwaters contribute large—but still poorly quantified—amounts of CO2 to the atmosphere. Conservative estimates imply that globally 36% (i.e., 0.93 Pg C yr−1) of total CO2 outgassing from rivers and streams originate from headwaters. We also discuss challenges in determination of CO2 sources, concentrations, and fluxes. To overcome uncertainties of CO2 sources and its outgassing from headwater streams on the global scale, new investigations are needed that should include groundwater data. Such studies would also benefit from applications of integral CO2 outgassing isotope approaches and multiscale geophysical imaging techniques.

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Section: Co2 Contents In Streamsmentioning

confidence: 99%

A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective

Marx

Dušek

Jankovec

et al. 2017

Reviews of Geophysics

270

216

View full text Add to dashboard Cite

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“…The soil hydraulic parameters that were used for the one‐dimensional dual‐continuum model are listed in Table . Soil hydraulic properties of the preferential flow domain (Table ) were estimated in our previous studies of soil water dynamics at Tomsovka (e.g., Dohnal, Dusek, & Vogel, ; Dohnal, Dusek, Vogel, Herza, & Tacheci, ; Dohnal, Vogel, Sanda, & Jelinkova, ; Dusek et al, ). We assumed that the volumetric fraction of the preferential flow domain varied linearly between 7% at the soil surface and 5% at the depth of 75 cm.…”

Section: Model Applicationmentioning

confidence: 99%

“…Parameters of the functions f ( θ ) and f ( T ) were taken from the literature (Dusek et al, ; Mei et al, ; Yurova et al, ). The water contents representing the optimum production and decomposition rates corresponded to pressure heads of –500 and –100 cm, respectively.…”

Section: Model Applicationmentioning

confidence: 99%

“…Sorption interactions of DOC with solid phases of the bulk soil were approximated using instantaneous (equilibrium) model based on a linear isotherm (Dusek et al, ). Other modelling studies suggested that kinetic reactions more accurately describe DOC adsorption/desorption (Fan, Neff, & Wickland, ; Mei, Hornberger, Kaplan, Newbold, & Aufdenkampe, ; Mei, Hornberger, Kaplan, Newbold, & Aufdenkampe, ; Yurova et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…The main disadvantage of a broader use of such physically based distributed models is associated with the inherent difficulty in their parameterization. This can be partially addressed by using the Monte Carlo framework (Dusek et al, ; Futter et al, ; Yurova et al, ). This approach is suitable for relatively well characterized and small catchments with areas of less than a few square kilometer.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Modelling multiseasonal preferential transport of dissolved organic carbon in a shallow forest soil: Equilibrium versus kinetic sorption

Dušek

Dohnal

Vogel

et al. 2019

Hydrological Processes

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Parameterization of transformation and transport processes of dissolved organic carbon (DOC) in soils is challenging especially under variable hydrological conditions. In this study, DOC concentrations in stormflow were analysed with a physically based modelling approach. A one‐dimensional dual‐continuum vertical flow and transport model was applied to simulate subsurface processes in a macroporous forest hillslope soil over a period of 4.5 years. Microbially mediated transformations of DOC were assumed to depend primarily on soil moisture and soil temperature. Two conceptually different descriptions of the sorption of DOC to soil were examined with equilibrium and kinetic approaches. In order to quantify the uncertainties associated with the model parameterization, Monte Carlo analyses in conjunction with Latin hypercube sampling was performed. Despite the complexity of microbial transformations, the simulated temporal patterns of DOC concentrations in stormflow showed similar behaviour to those reflected in the observed DOC fluxes. Due to preferential flow, the hillslope DOC export (5.0 ± 0.5 g C · m−2 · year−1) was higher than the amounts usually reported in the literature. Overall DOC transport in hillslope scenarios could be described appropriately using the equilibrium sorption assumption. The performed analyses showed that the inclusion of the kinetic description of DOC sorption only slightly improved the predictions of the DOC hillslope export. Moreover, influences of seasonal hydro‐climatological conditions on hillslope export of DOC could be observed. Reduced DOC transport during an extreme warm and dry summer was described with lower accuracy, thus indicating the difficulties in the representation of DOC transformations under dry conditions.

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Revealing subsurface processes in the Uhlířská catchment through combined modelling of unsaturated and saturated flow

Vitvar

Jankovec

Šanda

2022

Hydrological Processes

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A novel transferable modelling approach was applied to reveal subsurface flow processes and thus complement, verify, and enhance the conceptual knowledge of the small (1.78 km2) mountainous experimental catchment Uhlířská in the northern part of the Czech Republic. We used the S1D model to simulate flow and tracer movement in the vadose zone. MODFLOW‐2000, MODPATH and MT3DS models were used to determine residence time and flow trajectories in the saturated zone. The isotopic tracers 3H and 3H/3He were used to calibrate the groundwater model in the deeper aquifer layers. The modelling approach was established to enhance our understanding and quantification of interactions between the hillslope (82% of the area) and wetland (18% of the area), as well as the aquifer beneath the catchment. Numerical methods corroborated the estimated groundwater residence times and provided a catchment water balance in support of process knowledge. The combined modelling yielded the following water balance for the period 1961–2014: 1220 mm annual precipitation amount, 456 mm of percolation through the soil matrix domain on hillslopes, 534 mm of water through the hillslope preferential domain, and 22 mm of water through the matrix of the riparian wetland. This partitioning resulted in an area‐weighted average annual groundwater recharge of 430 mm. The water residence time on the hillslopes did not exceed 1 year, and was about 10 years for the saturated zone, with 20% of water older than 100 years in the deepest part of the aquifer. The conceptual knowledge of subsurface hydrological processes combined with numerical modelling, computation of water balance and isotope‐supported calibration is considered innovative, particularly the 3H/3He method to determine water residence times of young groundwater in the saturated zone. Lessons learned and recommendations are presented to apply the knowledge from the Uhlířská in the broad context of small research catchments.

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Dynamics of dissolved organic carbon in hillslope discharge: Modeling and challenges

Cited by 22 publications

References 90 publications

A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective

A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective

Modelling multiseasonal preferential transport of dissolved organic carbon in a shallow forest soil: Equilibrium versus kinetic sorption

Revealing subsurface processes in the Uhlířská catchment through combined modelling of unsaturated and saturated flow

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Dynamics of dissolved organic carbon in hillslope discharge: Modeling and challenges

Cited by 22 publications

References 90 publications

A review of CO2 and associated carbon dynamics in headwater streams: A global perspective

A review of CO2 and associated carbon dynamics in headwater streams: A global perspective

Modelling multiseasonal preferential transport of dissolved organic carbon in a shallow forest soil: Equilibrium versus kinetic sorption

Revealing subsurface processes in the Uhlířská catchment through combined modelling of unsaturated and saturated flow

Contact Info

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A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective

A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective