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| Titel |
Solute transport dynamics in small, shallow groundwater-dominated agricultural catchments: insights from a high-frequency, multisolute 10 yr-long monitoring study |
| VerfasserIn |
A. H. Aubert, C. Gascuel-Odoux, G. Gruau, N. Akkal, M. Faucheux, Y. Fauvel, C. Grimaldi, Y. Hamon, A. Jaffrézic, M. Lecoz-Boutnik, J. Molenat, P. Petitjean, L. Ruiz, P. Merot |
| 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 ; 17, no. 4 ; Nr. 17, no. 4 (2013-04-11), S.1379-1391 |
| Datensatznummer |
250018845
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| Publikation (Nr.) |
 copernicus.org/hess-17-1379-2013.pdf |
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| Zusammenfassung |
High-frequency, long-term and multisolute measurements are required to
assess the impact of human pressures on water quality due to (i) the high
temporal and spatial variability of climate and human activity and (ii) the
fact that chemical solutes combine short- and long-term dynamics. Such data
series are scarce. This study, based on an original and unpublished
time series from the Kervidy-Naizin headwater catchment (Brittany, France),
aims to determine solute transfer processes and dynamics that characterise
this strongly human-impacted catchment.
The Kervidy-Naizin catchment is a temperate, intensive agricultural
catchment, hydrologically controlled by shallow groundwater. Over 10 yr,
five solutes (nitrate, sulphate, chloride, and dissolved organic and
inorganic carbon) were monitored daily at the catchment outlet and roughly
every four months in the shallow groundwater.
The concentrations of all five solutes showed seasonal variations but the
patterns of the variations differed from one solute to another. Nitrate and
chloride exhibit rather smooth variations. In contrast, sulphate as well as
organic and inorganic carbon is dominated by flood flushes. The observed
nitrate and chloride patterns are typical of an intensive agricultural
catchment hydrologically controlled by shallow groundwater. Nitrate and
chloride originating mainly from organic fertilisers accumulated over
several years in the shallow groundwater. They are seasonally exported when
upland groundwater connects with the stream during the wet season.
Conversely, sulphate as well as organic and inorganic carbon patterns are not
specific to agricultural catchments. These solutes do not come from
fertilisers and do not accumulate in soil or shallow groundwater; instead,
they are biogeochemically produced in the catchment. The results allowed
development of a generic classification system based on the specific
temporal patterns and source locations of each solute. It also considers the
stocking period and the dominant process that limits transport to the
stream, i.e. the connectivity of the stocking compartment. This mechanistic
classification can be applied to any chemical solute to help assess its
origin, storage or production location and transfer mechanism in similar
catchments. |
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