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| Titel |
Dating of young groundwater in nine porous aquifers in Alpine Basins by 18O, 3H, 3H/3He, CFC and SF6 |
| VerfasserIn |
Martin Kralik, Franko Humer, George Darling, Jürgen Sültenfuß, Johannes Grath |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056767
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| Zusammenfassung |
| The European Water Framework Directive requires the surface and groundwater bodies in the
EU to be back to good quality conditions by 2015. For the implementation of this goal it is
necessary that any measures to improve groundwater quality show an impact within the
upcoming 5 years.
The investigated groundwater bodies are distributed all over Austria and range in size
between 160 - 1000 km2. The thickness of the aquifers varies 2 – 110m. The nine
groundwater bodies are distributed all over the Eastern Alps from the Upper Rhine valley
to the Vienna-area at the Austrian – Hungarian border. Most of them are under
intensive agricultural use and consist of fluvial gravel and sands. Due to the extensive
agricultural use it contains high concentrations of nitrate and pesticides and shows other
hydrochemical changes caused by urbanisation and industrial use. In more than 100
monitoring wells delta oxygen-18 was analysed four times during one year within the
framework of the Austrian hydrochemical groundwater monitoring system. During one
campaign 3H, 3H/3He, CFCs and SF6 was analysed in all wells. In addition, the
same methods were applied on depth-resolved groundwater samples at selected
wells.
The first results support the rapid water circulation in the inner-Alpine basins whereas the
basins at eastern end of the Alps within the Pannonian climate zone show transport times of
decades for the uppermost aquifer.
However, the fluvial sediments are partly very heterogeneous and the mean residence time
(MRT) can vary considerably from well to well in range of less than half a year to more than
50 years. The depth resolved groundwater samples indicate in most cases an increase of MRT
with depth. |
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