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| Titel |
Lead, zinc, and chromium concentrations in acidic headwater streams in Sweden explained by chemical, climatic, and land-use variations |
| VerfasserIn |
B. J. Huser, J. Fölster, S. J. Köhler |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 11 ; Nr. 9, no. 11 (2012-11-07), S.4323-4335 |
| Datensatznummer |
250007378
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| Publikation (Nr.) |
 copernicus.org/bg-9-4323-2012.pdf |
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| Zusammenfassung |
| Long-term data series (1996–2009) for eleven acidic headwater streams
(< 10 km2) in Sweden were analyzed to determine factors
controlling concentrations of trace metals. In-stream chemical data as well
climatic, flow, and deposition chemistry data were used to develop models
predicting concentrations of chromium (Cr), lead (Pb), and zinc (Zn). Data
were initially analyzed using partial least squares to determine a set of
variables that could predict metal concentrations across all sites. Organic
matter (as absorbance) and iron related positively to Pb and Cr, while pH
related negatively to Pb and Zn. Other variables such as conductivity,
manganese, and temperature were important as well. Multiple linear
regression was then used to determine minimally adequate prediction models
which explained an average of 35% (Cr), 52% (Zn), and 72% (Pb) of
metal variation across all sites. While models explained at least 50% of
variation in the majority of sites for Pb (10) and Zn (8), only three sites
met this criterion for Cr. Investigation of variation between site models
for each metal revealed geographical (altitude), chemical (sulfate), and
land-use (silvaculture) influences on predictive power of the models.
Residual analysis revealed seasonal differences in the ability of the models
to predict metal concentrations as well. Expected future changes in model
variables were applied and results showed the potential for long-term
increases (Pb) or decreases (Zn) for trace metal concentrations at these
sites. |
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