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| Titel |
Granulometric characterization of sediments transported by surface runoff generated by moving storms |
| VerfasserIn |
J. L. M. P. Lima, C. S. Souza, V. P. Singh |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 15, no. 6 ; Nr. 15, no. 6 (2008-12-16), S.999-1011 |
| Datensatznummer |
250012815
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| Publikation (Nr.) |
 copernicus.org/npg-15-999-2008.pdf |
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| Zusammenfassung |
| Due to the combined effect of wind and rain, the
importance of storm movement to surface flow has long been recognized, at
scales ranging from headwater scales to large basins. This study presents
the results of laboratory experiments designed to investigate the influence
of moving rainfall storms on the dynamics of sediment transport by surface
runoff. Experiments were carried out, using a rain simulator and a soil
flume. The movement of rainfall was generated by moving the rain simulator
at a constant speed in the upstream and downstream directions along the
flume. The main objective of the study was to characterize, in laboratory
conditions, the distribution of sediment grain-size transported by
rainfall-induced overland flow and its temporal evolution. Grain-size
distribution of the eroded material is governed by the capacity of flow that
transports sediments. Granulometric curves were constructed using
conventional hand sieving and a laser diffraction particle size analyser
(material below 0.250 mm) for overland flow and sediment deliveries
collected at the flume outlet. Surface slope was set at 2%, 7% and 14%.
Rainstorms were moved with a constant speed, upslope and downslope, along
the flume or were kept static. The results of laboratory experiments show
that storm movement, affecting the spatial and temporal distribution of
rainfall, has a marked influence on the grain-size characteristics of
sediments transported by overland flow. The downstream-moving rainfall
storms have higher stream power than do other storm types. |
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