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| Titel |
Three-year sediment transport in a highly erodible catchment: The River Isabena (Ebro Basin, Southern Pyrenees) |
| VerfasserIn |
J. A. López-Tarazón, R. J. Batalla, D. Vericat |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019451
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| Zusammenfassung |
| Quantifying suspended sediment load is important in catchments containing highly erodible
materials, especially in those that drain into reservoirs since high suspended yields generates
and exacerbates reservoirs siltation. Suspended sediment records are also essential for the
calibration and validation of numerical models that aim to reproduce past soil erosion and
sediment dynamics and to generate reliable data for management purposes. The River
Isabena is a mesoscale (445 km2) mountainous catchment located in the Southern Central
Pyrenees in the Iberian Peninsula. The river experiences frequent floods, a characteristic
that, together with the high connectivity between its network and the sediment
sources, keeps sediment transport rates relatively high; instantaneous suspended
sediment concentration occasionally attains 300 g l-1. The main sources of fine
sediment are badland areas on marls (occupying less than 1% of the catchment area).
The river flows into the Barasona Reservoir that experiences historical siltation
problems.
In order to quantify the suspended sediment transport in the Isabena basin, water and
suspended sediment were monitored during the period 2005-2007. Discharge was sampled at
the downstream end of the catchment. Suspended sediment transport was measured
continuously at the same section by combining high-range turbidimeter readings and water
samples (obtained regularly using and automatic sampler and manually -DH54 sampler-
during floods). A total of 80 floods have been sampled during the study period. Total
sediment yield has been estimated at 552,760 tones, representing an annual average of
184,253 t yr-1, and an averaged specific sediment yield (hereafter SSY) of 414 t
km-2 yr-1. Most studies that showed a similar range of SSY are restricted to small
mountainous catchments ( |
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