 |
| Titel |
The Fischa-Dagnitz spring, Southern Vienna Basin: a multi tracer time series study re-assessing earlier conceptual assumptions. |
| VerfasserIn |
Axel Suckow, Christoph Gerber, Martin Kralik, Jürgen Sültenfuß, Roland Purtschert |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077818
|
|
|
|
|
|
| Zusammenfassung |
| The gravel aquifer of the Southern Vienna Basin is a very important backup drinking water
resource for the city of Vienna. A discharge location, the Fischa-Dagnitz spring in the
Southern Vienna Basin, Austria, was re-investigated in 2011, five years after the
gas exchange tracer test published in (Stolp et al., 2010), and sampled for stable
isotopes 18O/2H, tritium, 3He, SF6 and 85Kr (Gerber et al., 2012). Additionally, new
tritium time series data (Davis et al., 1967), previously not considered in Stolp et al.
(2010), were included. These show a higher and earlier tritium peak of >300 TU in
1965 in the discharge of the Fischa-Dagnitz spring as compared to 221 TU in 1972
considered in Stolp et al. (2010). The new 3He, SF6 and 85Kr gas tracer data from
2011 confirm the earlier finding for 3He of Stolp et al. (2010) and indicate a more
recent equilibration with the atmosphere than the water bound tracers 18O, 2H and
tritium.
A new modelling attempt using the Lumpy code (Suckow, 2012) confirmed the
discrepancy between the tritium data and the gaseous tracers 3He, SF6 and 85Kr. No
steady-state combination of local recharge (represented by an exponential model) and
Schwarza river infiltration flowing through the gravel aquifer (represented by a parallel
dispersion model) can equally well explain both the tritium time series and the gas tracer
results.
A revised conceptual model proposes that a pinching of the aquifer at unconformities
in the gravel body or a fault zone known in the gravel body forces groundwater
along the flow path closer to the surface and exposes it to the atmosphere. This
would tend to reset the “dating” clock for the gaseous tracers 3He, SF6 and 85Kr,
which can equilibrate quickly with the atmosphere, but not for tritium, which marks
the transport behaviour of the water itself. These findings are of importance also
for other multi-tracer assessments of groundwater movement in phreatic aquifer
systems.
References:
Davis, G.H., Payne, B.R., Dincer, T., Florkowski, T., Gattinger, T., 1967. Seasonal
Variations in the Tritium Content of Groundwaters of the Vienna Basin, Austria, Isotope
Hydrology 1967. IAEA, Vienna, Austria, IAEA, Vienna, Austria, pp. 451-473.
Gerber, C., Purtschert, R., Kralik, M., Humer, F., Sültenfuss, J., Darling, G.W.,
Gooddy, D., 2012. Suitability and potential of environmental tracers for base-flow
determination in streams: EGU2012-14066, EGU 12. European Geosciences Union,
Vienna
Stolp, B.J., Solomon, D.K., Suckow, A., Vitvar, T., Rank, D., Aggarwal, P.K., Han, L.-F.,
2010. Age dating base flow at springs and gaining streams using helium-3 and tritium:
Fischa-Dagnitz system, southern Vienna Basin, Austria. Water Resources Research
46.
Suckow, A., 2012. Lumpy - an interactive Lumped Parameter Modeling code based on
MS Access and MS Excel., EGU 12. European Geosciences Union, Vienna |
|
|
|
|
|
|