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| Titel |
Improved understanding of solute concentration-discharge dynamics through state-of-the-art antecedent moisture content (AMC) monitoring and analysis |
| VerfasserIn |
A. O. Eludoyin, R. Brazier, T. Quine, R. Bol, R. Orr, B. Griffith |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058760
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| Zusammenfassung |
| The relationship between solute/sediment concentration and discharge (c-Q) can be neither
understood nor predicted without full understanding of the antecedent moisture content
(AMC). Many preceding studies have ignored this variable in part because of the problems
associated with accurate and full documentation of AMC. This study presents new
insights into the control of AMC on c-Q made possible through work on the uniquely
well-instrumented ‘NorthWyke Farm Platform’ which was commissioned in April
2011 as a UK national capability for collaborative research, training and knowledge
exchange in agro-environmental sciences for agricultural productivity and ecosystem
responses to different management practices. The Farm Platform was designed into 15
hydrological units based on a predicted 50-year flood event, each with H-flume at
catchment outlet. 9.2 km of French drains were installed at 800mm soil depth with
perforated plastic drainage pipe installed to collect surface and near surface flow from
the catchments. Each flume receives flow from 2 branches of each French drain
system and discharges via concrete piping and a sampling pit. Where required the
catchment is protected from groundwater seepage and surface runoff ingress from
adjacent catchment with open ditches and sealed pipes. Discharge is measured at each
flume with an ISCO bubbler flowmeter, and concentrations of Total Organic Carbon
(TOC), Ammonium (NH4-N), Nitrate (NO3-N), Dissolved Oxygen (DO), total
Phosphorus, chloride, pH and turbidity are monitored at 15 minutes intervals. In
addition, rainfall, soil temperature and soil moisture are monitored at the same
timestep. This study analyses discharge and soil moisture data alongside TOC,
NO3-N and PO4-P at 15 min intervals in rain events between November 28 and
December 13, 2011. Soil moisture exhibited moderately strong relationships with TOC
and NO3 (r -¥ -0.38; p-¤0.05), but a weak one with PO4. Discharge, on the other
hand, exhibited a weak (r -¤0.08; p>0.05) with all the ions. These results suggest
that the behaviour of these ions is not explained by discharge alone. Analysis is in
progress to determine the influence of soil moisture on hysteresis loops of these
ions, as well as their contribution, with other end members to runoff in this study. |
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