Graham etal 2012 JHE.pdf (1.82 MB)
Conversions of surface grain-size samples collected and recorded using different procedures
journal contribution
posted on 2012-06-06, 12:52 authored by David GrahamDavid Graham, Anne-Julia Rollet, Stephen Rice, Herve PiegayInformation about the grain-size distribution of the surface layer of sediment exposed on river
beds is often critical in studies of fluvial hydraulics, geomorphology and ecology. A variety
of sampling and analysis techniques are in common usage which produce grain-size
distributions that are not directly comparable. This paper seeks to explore the appropriate
conversions between different types of surface grain-size sampling methods. This is
particularly timely in the light of increasingly widespread use of automatic and semiautomatic
image-based measurement methods, the comparability of which with conventional
measurement methods is relatively poorly constrained. For conversions between area-bynumber
(paint-and-pick) and grid-by-number (pebble count) samples, the empirically-derived
conversion factor (±2.2) was found to be greater than that predicted by the Kellerhals and
Bray model (±2), but the errors associated with using the value predicted by the model were
small (3.8% in mm). For conversions between areal samples recorded by count and weight, the empirically-derived conversion factor was approximately ±2.9, but the use of the value
predicted by the Kellerhals and Bray model (±3) resulted in only small errors (5.2% in mm).
Similarly, for conversions between image-based grain-size distributions recorded in area-bynumber
and grid-by number form, the emipirically-derived conversion factor was ±1.9, but
the using the model value of ±2 resulted in only small errors (4.1% in mm). Although these
results are specific to the datasets analysed, the variety of sedimentary conditions included
gives us confidence that the results are representative.
History
School
- Social Sciences
Department
- Geography and Environment
Citation
GRAHAM, D.J. ... et al, 2012. Conversions of surface grain-size samples collected and recorded using different procedures. Journal of Hydraulic Engineering, 138 (10), pp.839–849.Publisher
© ASCE (American Society of Civil Engineers)Version
- AM (Accepted Manuscript)
Publication date
2012Notes
This article was published in the Journal of Hydraulic Engineering [© American Society of Civil Engineers] and the definitive version is available at: http://dx.doi.org/10.1061/(ASCE)HY.1943-7900.0000595ISSN
0733-9429eISSN
1943-7900Publisher version
Language
- en