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Titel |
Hydrochemical variability at the Upper Paraguay Basin and Pantanal wetland |
VerfasserIn |
A. T. Rezende Filho, S. Furian, R. L. Victoria, C. Mascré, V. Valles, L. Barbiero |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 8 ; Nr. 16, no. 8 (2012-08-14), S.2723-2737 |
Datensatznummer |
250013423
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Publikation (Nr.) |
copernicus.org/hess-16-2723-2012.pdf |
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Zusammenfassung |
Compartmentalization is a prerequisite to understand large wetlands that
receive water from several sources. However, it faces the heterogeneity in
space and time, resulting from physical, chemical and biological processes
that are specific to wetlands. The Pantanal is a vast seasonally flooded
continental wetland located in the centre of South America. The chemical
composition of the waters that supply the Pantanal (70 rivers) has been
studied in order to establish a compartmentalization of the wetland based on
soil-water interactions. A PCA-based EMMA (End-Members Mixing Analysis)
procedure shows that the chemistry of the rivers can be viewed as a mixture
of 3 end-members, influenced by lithology and land use, and delimiting large
regions. Although the chemical composition of the end-members changed
between dry and wet seasons, their spatial distribution was maintained. The
results were extended to the floodplain by simple tributary mixing
calculation according to the hydrographical network and to the areas of
influence for each river when in overflow conditions. The resulting map
highlights areas of high geochemical contrast on either side of the river
Cuiaba in the north, and of the rivers Aquidauana and Abobral in the south.
The PCA-based treatment on a sampling conducted in the Nhecol-ndia, a
large sub region of the Pantanal, allowed the identification and ordering of
the processes that control the geochemical variability of the surface
waters. Despite an enormous variability in electrical conductivity and pH,
all data collected were in agreement with an evaporation process of the
Taquari River water, which supplies the region. Evaporation and associated
saline precipitations (Mg-calcite, Mg-silicates K-silicates) explained more
than 77% of the total variability in the chemistry of the regional
surface water sampling. |
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