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| Titel |
Influence of quick groundwater recharge on base flow in karstic catchments |
| VerfasserIn |
Yan Liu, Christiane Zarfl, Nandita B. Basu, Olaf A. Cirpka |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143571
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| Publikation (Nr.) |
 EGU/EGU2017-7304.pdf |
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| Zusammenfassung |
| Flow from karst springs is important for the groundwater flow and its recharge which, in turn
can determine the pattern of base flow. This behaviour can be well observed in the Ammer
catchment, located in southwestern Germany. It covers an area of approximately 130.5 km2
with several karst springs contributing most of the groundwater flow to the Ammer River. Its
discharge shows a very special behaviour with a sharp increase every winter. It is supposed
that the groundwater storage layer of this catchment can store large volumes of water because
of karstification of the aquifers. Recharge from the subsurface storage to the groundwater
storage when subsurface storage reaches a threshold makes groundwater storage
increase rapidly, which is also reflected in a quickly rising base flow. We set up a
semi-distributed hydrologic model to reproduce this behaviour and gain additional
insights on the underlying processes of these discharge dynamics. The model is
composed out of three main components: soil moisture, subsurface storage and
groundwater storage. Besides percolation from subsurface storage to groundwater
storage, quick recharge was introduced into this model for interpreting the sharp
rise of base flow. This model was used for five years of simulation (from 2003 to
2007). Results indicate that: (a) percolation is an every day process whereas quick
recharge only occurs over few days within a year, mostly from December to April and
also in June when precipitation is very large; (b) the annual average recharge from
percolation and quick recharge account for 18% and 82% of the total groundwater
recharge, respectively, but the quick recharge rate is seven times higher than the
percolation rate; and (c) for a single event of sharp increase in base flow quick
recharge contributes 70%-78% to groundwater recharge, but in case of a single
event of gradual increase of the base flow quick recharge contributes only 30%. |
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