Warburton, J. (1990)
Comparison of bed load yield estimates for a glacial meltwater stream
Article
- Cite key
- Warburton1990a
- Language
- en
- Journal
- Hydrology in Mountainous Regions. I - Hydrologicat Measurements; theWater Cycle
- Volume
- Proceeding of two Lausanne Symposia
- Pages
- 315-323
- URL
- http://iahs.info/redbooks/a193/iahs_193_0315.pdf
- Description
- Estimates of bed load yield in mountain streams can be
made using three principal methods: sediment traps, sediment rating
curves and sediment transport formulae. This paper compares these
three techniques for estimating the bed load yield in the Bas Glacier
d'Arolla proglacial stream (Valais, Switzerland) for May-September
1987. This stream is a steep (0.07 m m"
1
), coarse-bed, boulder and
cobble channel. Bed load yield estimates are provided by a selfpurging sediment trap; a bed load rating curve constructed from a
program of Helley-Smith bed load sampling; and loads calculated
using the Schoklitsch sediment transport formula. The sediment trap
estimate is taken as a reference for die evaluation of the site-specific
bed load rating curve and the Schoklitsch formula. Results for 1987
show that both methods over-predict yields; die bed load rating curve
by 36% and me Schoklitsch formula by 111%. These discrepancies
arise due to temporal and spatial variation in transport rates, problems
in defining "active bed" width and difficulty in characterising a
representative particle size for the critical direshold of bed material
movement.