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| Titel |
Drivers on carbon dioxide emissions from the Scheldt river basin |
| VerfasserIn |
Nathalie Gypens, Paul Passy, Josette Garnier, Gilles Billen, Marie Silvestre, Alberto V. Borges |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250095304
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| Publikation (Nr.) |
 EGU/EGU2014-10752.pdf |
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| Zusammenfassung |
| Inland waters are a key component of the global carbon (C) cycle that transport organic and
inorganic C from the terrestrial biosphere to the coastal ocean and emit CO2 to the
atmosphere at a significant rate for global CO2 budgets. Yet, mechanisms underlying this
CO2 emission to the atmosphere remain poorly understood and seldom modelled
mechanistically.
For this application a module describing the carbonate system and CO2 air-water
exchange was added to the biogeochemical Seneque/Riverstrahler model describing
transformation of C, N, P, Si occurring within hydrological networks. The model was applied
to the human impacted Scheldt basin and the evolution of the partial pressure of CO2 (pCO2)
and air-water CO2 flux was simulated for the year 1997 when data of dissolved inorganic
carbon (DIC), total alkalinity (TA) and pCO2 are available for model validation. The model
reproduces reasonably well the seasonal and spatial variations of the DIC, TA and
pCO2 within the 5 main rivers of the Scheldt basin where data are available. At the
annual level, the studied rivers act as major sources of CO2 to the atmosphere.
Results show that the longitudinal variations of pCO2 are mainly controlled by the
importance of air-water CO2 exchange. However, the choice of the parameterization
of the gas transfer coefficient does not appear critical for this particular system.
Biological activity also locally modulates the longitudinal variations of pCO2, while
diffuse inputs from the watershed determine the initial conditions in the river without
significantly altering the patterns observed from the upstream to the downstream.
Both diffuse and punctual sources of C and TA are important drivers of the CO2
exchange in the river. In particular, model application evidences the sensitivity of
the simulated CO2 fluxes to the description of human activities on the watershed. |
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