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Titel |
Sediment sources in the Upper Severn catchment: a fingerprinting approach |
VerfasserIn |
A. L. Collins, D. E. Walling, Graham J. L. Leeks |
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 ; 1, no. 3 ; Nr. 1, no. 3, S.509-521 |
Datensatznummer |
250000194
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Publikation (Nr.) |
copernicus.org/hess-1-509-1997.pdf |
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Zusammenfassung |
Suspended sediment sources in the Upper Severn catchment
are quantified using a composite fingerprinting technique combining statistically-verified
signatures with a multivariate mixing model. Composite fingerprints are developed from a
suite of diagnostic properties comprising trace metal (Fe, Mn, AI), heavy metal (Cu, Zn, Pb,
Cr, Co, Ni), base cation (Na, Mg, Ca, K), organic (C, N), radiometric (137Cs,
210Pb), and other (total P) determinands. A numerical mixing model, to compare
the fingerprints of contemporary catchment source materials with those of fluvial
suspended sediment in transit and those of recent overbank floodplain deposits, provides
a means of quantifying present and past sediment sources respectively. Sources are
classified in terms of eroding surface soils under different land uses and channel banks.
Eroding surface soils are the most important source of the contemporary suspended sediment
loads sampled at the Institute of Hydrology flow gauging stations at Plynlimon and at
Abermule. The erosion of forest soils, associated with the autumn and winter commercial
activities of the Forestry Commission, is particularly evident. Reconstruction of sediment
provenance over the recent past using a sediment core from the active river floodpiain
at Abermule, in conjunction with a 137Cs chronology, demonstrates the
significance of recent phases of afforestation and deforestation for accelerated catchment
soil erosion. |
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