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| Titel |
Impacts of climate variability on wetland salinization in the North American prairies |
| VerfasserIn |
U. Nachshon, A. Ireson, G. van der Kamp, S. R. Davies, H. S. Wheater |
| 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 ; 18, no. 4 ; Nr. 18, no. 4 (2014-04-01), S.1251-1263 |
| Datensatznummer |
250120320
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| Publikation (Nr.) |
 copernicus.org/hess-18-1251-2014.pdf |
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| Zusammenfassung |
The glaciated plains of the North American continent, also known as the
"prairies", are a complex hydrological system characterized by hummocky
terrain, where wetlands, containing seasonal or semi-permanent ponds, occupy
the numerous topographic depressions. The prairie subsoil and many of its
water bodies contain high salt concentrations, in particular sulfate salts,
which are continuously cycled within the closed drainage basins. The period
between 2000 and 2012 was characterized by an unusual degree of climatic
variability, including severe floods and droughts, and this had a marked
effect on the spatial distribution, water levels and chemical composition of
wetland ponds. Understanding the geochemical and hydrological processes
under changing environmental conditions is needed in order to better
understand the risk and mitigate the impacts of future soil and water
salinization.
Here we explore salt dynamics in the prairies using field observations from
St. Denis, Saskatchewan, taken mostly over the last 20 years. Measurements
include meteorological data, soil moisture, soil salinity, groundwater
levels and pond water volume, salinity, and chemical composition. The record
includes periods of exceptional snow (1997, 2007) and periods of exception
rainfall (2010, 2012), both of which resulted in unusually high pond water
levels. Measurements indicated that severe pond salinization only occurred
in response to extreme summer rainfall. It is hypothesized that since
rainfall water infiltrates through the soil towards the depressions, while
snowmelt water flows mainly as surface water over frozen soils, they have
markedly different impacts on salt transport and pond salinization. Whilst
this hypothesis is consistent with our conceptual understanding of the
system, it needs to be tested further at a range of field sites in the prairies. |
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