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Titel |
Can we predict groundwater discharge from terrestrial ecosystems using existing eco-hydrological concepts? |
VerfasserIn |
A. P. O'Grady, J. L. Carter, J. Bruce |
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 ; 15, no. 12 ; Nr. 15, no. 12 (2011-12-15), S.3731-3739 |
Datensatznummer |
250013053
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Publikation (Nr.) |
copernicus.org/hess-15-3731-2011.pdf |
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Zusammenfassung |
There is increasing recognition of the role that groundwater plays in the
maintenance of ecosystem structure and function. As a result, water
resources planners need to develop an understanding of the water
requirements for these ecosystems. In this study we reviewed estimates of
groundwater discharge from terrestrial vegetation communities around
Australia and explored this data set for empirical relationships that could
be used to predict groundwater discharge in data poor areas. In particular
we explored how leaf area index and the water balance of groundwater systems
conformed to two existing ecohydrological frameworks; the Budyko framework,
which describes the partitioning of rainfall into evapotranspiration and
runoff within a simple supply and demand framework, and Eagleson's theory of
ecological optimality. We demonstrate strong convergence with the
predictions of both frameworks. Terrestrial groundwater systems discharging
groundwater lie above the water limit line as defined in the Budyko
framework. However, when climate wetness was recalculated to include
groundwater discharge there was remarkable convergence of these sites along
this water limit line. Thus, we found that there was a strong correlation
between estimates of evapotranspiration derived from the Budyko's
relationship with observed estimates of evapotranspiration. Similarly, the
LAI of ecosystems with access to groundwater have higher LAI than those without
access to groundwater, for a given climatic regime. However, again when
discharge was included in the calculation of climate wetness index there was
again strong convergence between the two systems, providing support for
ecological optimality frameworks that maximize LAI under given water
availability regimes. The simplicity and utility of these simple
ecohydrological insights potentially provide a valuable tool for predicting
groundwater discharge from terrestrial ecosystems, especially in data poor
areas. |
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