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Titel |
From precipitation to groundwater baseflow in a native prairie ecosystem: a regional study of the Konza LTER in the Flint Hills of Kansas, USA |
VerfasserIn |
D. R. Steward, X. Yang, S. Y. Lauwo, S. A. Staggenborg, G. L. Macpherson, S. M. Welch |
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. 10 ; Nr. 15, no. 10 (2011-10-20), S.3181-3194 |
Datensatznummer |
250012995
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Publikation (Nr.) |
copernicus.org/hess-15-3181-2011.pdf |
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Zusammenfassung |
Methods are developed to study hydrologic interactions across the
surficial/groundwater interface in a native prairie ecosystem. Surficial
ecohydrologic processes are simulated with the USDA's EPIC model using daily
climate data from the Kansas Weather Data Library, vegetation and soil data
from the USDA, and current land-use management practices. Results show that
mean annual precipitation (from 1985–2005) is partitioned into 13% runoff
regionally and 14% locally over the Konza LTER, lateral flow through soil
is 1% regionally and 2% locally, groundwater recharge is 11%
regionally and 9% locally, and evapotranspiration accounts for the
remaining 75%. The spatial distribution of recharge was used in a regional
Modflow groundwater model that was calibrated to existing groundwater
observations and field measurements gathered for this study, giving a
hydraulic conductivity in the Flint Hills region of 1–2 m day−1 with
a local zone (identified here) of 0.05–0.1 m day−1.
The resistance was set to fixed representative values during model
calibration of hydraulic conductivity, and simple log-log relations correlate
the enhanced recharge beneath ephemeral upland streams and baseflow in
perennial lowland streams to the unknown resistance of the streambeds.
Enhanced recharge due to stream transmission loss (the difference between
terrestrial runoff and streamflow) represents a small fraction of streamflow
in the ephemeral upland and the resistance of this streambed is
100 000 day. Long-term baseflow in the local Kings Creek watershed (2%
of the groundwater recharge over the watershed) is met when the resistance of
the lowland streambed is 1000 day. The coupled framework developed here to
study surficial ecohydrological processes using EPIC and groundwater
hydrogeological processes using Modflow provides a baseline hydrologic
assessment and a computational platform for future investigations to examine
the impacts of climate change, vegetative cover, soils, and management
practices on hydrologic forcings. |
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