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| Titel |
Using water chemistry time series to model dissolved inorganic carbon dynamics in the western Amazon basin |
| VerfasserIn |
Leena Vihermaa, Susan Waldron, Jason Newton |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076541
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| Zusammenfassung |
| Two small streams (New Colpita and Main Trail) and two rivers (Tambopata and La Torre), in
the Tambopata National Reserve, Madre de Dios, Peru, were sampled for water chemistry
(conductivity, pH and dissolved oxygen) and hydrology (stage height and flow velocity). In
the small streams water chemistry and hydrology variables were logged at 15 minute intervals
from Feb 2011 to November 2012. Water samples were collected from all four channels
during field campaigns spanning different seasons and targeting the hydrological extremes.
All the samples were analysed for dissolved inorganic carbon (DIC) concentration and
δ13C (sample size ranging from 77 to 172 depending on the drainage system) and a
smaller subset for dissolved organic carbon (DOC) and particulate organic carbon
(POC) concentrations. Strong positive relationships were found between conductivity
and both DIC concentration and δ13C in the New Colpita stream and the La Torre
river. In Tambopata river the trends were less clear and in the Main Trail stream
there was very little change in DIC and isotopic composition. The conductivity data
was used to model continuous DIC time series for the New Colpita stream. The
modelled DIC data agreed well with the measurements; the concordance correlation
coefficients between predicted and measured data were 0.91 and 0.87 for mM-DIC
and δ13C-DIC, respectively. The predictions of δ13C-DIC were improved when
calendar month was included in the model, which indicates seasonal differences
in the δ13C-DIC conductivity relationship. At present, continuous DIC sampling
still requires expensive instrumentation. Therefore, modelling DIC from a proxy
variable which can be monitored continuously with ease and at relatively low cost,
such as conductivity, provides a powerful alternative method of DIC determination. |
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