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| Titel |
Validating the regional hydrogeological models with stable isotope data in precipitation |
| VerfasserIn |
Andis Kalvāns, Alise Babre, Konārds Popovs, Andrejs Timuhins, Aivars Spalviņš |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250131619
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| Publikation (Nr.) |
 EGU/EGU2016-12047.pdf |
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| Zusammenfassung |
| Stable isotopes 18O and 2H are a conservative tracer in the subsurface flow. The precipitation
is the primary input in the groundwater systems, hens’ there should be a positive regional
correlation of the stable isotope values in the groundwater and precipitation. The local
recharge peculiarities should modulate the precipitation isotope signal and introduce some
noise but not eliminate the correlation completely.
Modelled isotope values in the precipitation (Terzer et al. 2013) were compared to the
actually observed values in the groundwater (Babre et al, in print) in the Baltic Artesian
Basin, located at the South-East cost of the Baltic Sea. But positive and significant correlation
was not found. Two regional hydrogeological models LAMO (Spalvins et al. 2015) and
MOSYS (Virbulis et al. 2013) were used to trace the likely recharge area of the considered
groundwater samples. A simple particle tracing of the LAMO produced a statistically
significant, positive correlation between observed δ18O values in the relatively young
groundwater (modelled residence time <7500 years) and precipitation at the location of the
recharge. More complicated modelling system MOSYS with coarser resolution
allowed to simulate the large scale downward depletion of the δ18O values in the
groundwater.
It is concluded that observed stable isotope values in the groundwater can be compared to
the precipitation values in the recharge areas to validate the modelled regional flow
patterns.
This research is supported by Latvian National Research Programme EVIDENnT project
“Groundwater and climate scenarios”.
References
Babre, A., Kalv¯a ns, K., Popovs, K., Retiķe, I., D¯e liņa, A., Vaikmäe, R., Martma, T. (in
print) New isotope data in groundwater from Latvia, central part of the Baltic Basin. Isotopes
in Environmental & Health Studies
Spalvins, A., Slangens j., L¯a ce I., Aleks¯a ns, O., Krauklis, K., 2015. Improvement of
Hydrogeological Models: A Case Study. In International Review on Modelling and
Simulations (I.RE.MO.S.), Praise Worthy Prize, Naples, Italy, 8, pp. 266–276.
Terzer, S., Wassenaar, L. I., Araguás-Araguás, L. J., Aggarwal, P. K., 2013.
Global Isoscapes for δ18O and δ2H in Precipitation: Improved Prediction Using
Regionalized Climatic Regression Models. Hydrology and Earth System Sciences 17, pp.
4713–4728
Virbulis, J., Bethers U., Saks T., Sennikovs, J., Timuhins, A., 2013. Hydrogeological
Model of the Baltic Artesian Basin. Hydrogeology Journal, 21, pp. 845–862 |
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