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Titel |
Changes in discharge and solute dynamics between hillslope and valley-bottom intermittent streams |
VerfasserIn |
S. Bernal, F. Sabater |
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 ; 16, no. 6 ; Nr. 16, no. 6 (2012-06-04), S.1595-1605 |
Datensatznummer |
250013322
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Publikation (Nr.) |
copernicus.org/hess-16-1595-2012.pdf |
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Zusammenfassung |
To gain understanding on how alluvial zones modify water and nutrient export
from semiarid catchments, we compared monthly discharge as well as stream
chloride, carbon, and nitrogen dynamics between a hillslope catchment and a
valley-bottom catchment with a well-developed alluvium. Stream water and
solute fluxes from the hillslope and valley-bottom catchments showed
contrasting patterns between hydrological transitions and wet periods,
especially for bio-reactive solutes. During transition periods, stream water
export decreased >40% between the hillslope and the valley bottom
coinciding with the prevalence of stream-to-aquifer fluxes at the alluvial
zone. In contrast, stream water export increased by 20–70% between the
hillslope and valley-bottom catchments during wet periods. During transition
periods, stream solute export decreased by 34–97% between the hillslope
and valley-bottom catchments for chloride, nitrate, and dissolved organic
carbon. In annual terms, stream nitrate export from the valley-bottom
catchment (0.32 ± 0.12 kg N ha−1 yr−1 [average ± standard
deviation]) was 30–50% lower than from the hillslope catchment (0.56 ± 0.32 kg N ha−1 yr−1). The annual export of dissolved organic
carbon was similar between the two catchments (1.8 ± 1 kg C ha−1 yr−1). Our results suggest that hydrological retention in the alluvial
zone contributed to reduce stream water and solute export from the
valley-bottom catchment during hydrological transition periods when
hydrological connectivity between the hillslope and the valley bottom was
low. |
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