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| Titel |
Upscaling of lysimeter measurements to regional groundwater nitrate distribution |
| VerfasserIn |
Gernot Klammler, Johann Fank, Hans Kupfersberger, Gerhard Rock |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105462
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| Publikation (Nr.) |
 EGU/EGU2015-4987.pdf |
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| Zusammenfassung |
| For many European countries nitrate leaching from the soil zone into the aquifer due to
surplus application of mineral fertilizer and animal manure by farmers constitutes the most
important threat to groundwater quality. This is a diffuse pollution situation and measures to
change agricultural production have to be investigated at the aquifer scale to safeguard
drinking water supply from shallow groundwater resources
Lysimeters are state-of-the-art measurements for water and solute fluxes through the
unsaturated zone towards groundwater at the point scale, but due to regional heterogeneities
(especially concerning soil conditions) lysimeters cannot provide aquifer-wide groundwater
recharge and solute leaching. Thus, in this work the numerical simulation model
SIMWASER/STOTRASIM (Stenitzer, 1988; Feichtinger, 1998) for quantifying groundwater
recharge and nitrate leaching at aquifer scale is applied. Nevertheless, according to
Groenendijk et al. (2014) a model calibration by means of lysimeter measurements
is essential, since uncalibrated models are generally far from acceptable. Thus,
a lysimeter provides the basis for the parameterization of numerical simulation
models.
To quantify also the impact on regional nitrate distribution in the groundwater, we couple
the unsaturated zone model SIMWASER/STOTRASIM with the saturated groundwater flow
and solute transport model FELOW (Diersch, 2009) sequentially. In principal, the problem
could be solved by the 3 dimensional equation describing variable saturated groundwater flow
and solute transport. However, this is computationally prohibitive due to the temporal and
spatial scope of the task, particularly in the framework of running numerous simulations to
compromise between conflicting interests (i.e. good groundwater status and high
agricultural yield). To account for the unknown regional distribution of crops grown and
amount, timing and kind of fertilizers used a stochastic tool (Klammler et al, 2011)
is developed that generates sequences of crop rotations derived from municipal
statistical data. Required retention and unsaturated hydraulic conductivity curves
are derived from information out of the Austrian Soil Mapping (BMLF, 1974) by
pedotransferfunctions.
In summary, we present a method to quantify the temporal and spatial nitrate distribution
at the aquifer scale with focus on the importance of lysimeter measurements also for
modelling issues.
BMLF (1974) Österreichische Bodenkartierung – Erläuterungen zur Bodenkarte 1:25.000
(Kartierungsbereich Leibnitz, Steiermark). Bundesministerium für Land- und Forstwirtschaft,
Vienna, Austria
Diersch HJG (2009) FEFLOW Reference Manual, DHI-WASY GmbH, Berlin
Feichtinger, F. (1998). STOTRASIM - Ein Modell zur Simulation der Stickstoffdynamik
in der ungesättigten Zone eines Ackerstandortes. Schriftenreihe des Bundesamtes für
Wasserwirtschaft, Bd. 7, 14-41.
Groenendijk, P., M. Heinen, G. Klammler, J. Fank, H. Kupfersberger, V. Pisinaras, A.
Gemitzi, S. Peña-Haro, A. García-Prats, M. Pulido-Velazquez, A. Perego, M. Acutis, M.
Trevisan (2014): Performance assessment of nitrate leaching models for highly
vulnerable soils used in low-input farming based on lysimeter data. Sci. Tot. Environ.
499:463-480.
Klammler, G., Rock, G., Fank, J. & H. Kupfersberger, H. (2011): Generating land use
information to derive diffuse water and nitrate transfer as input for groundwater modelling at
the aquifer scale, Proc of MODELCARE 2011 Models – Repository of Knowledge,
Leipzig.
Stenitzer, E. (1988). SIMWASER - Ein numerisches Modell zur Simulation des
Bodenwasserhaushaltes und des Pflanzenertrages eines Standortes. Mitteilung Nr. 31,
Bundesanstalt für Kulturtechnik und Bodenwasserhaushalt, A-3252 Petzenkirchen. |
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