Sampling Heterogeneous Deposits in Gravel-Bed Streams
Publication: Journal of Hydraulic Engineering
Volume 123, Issue 12
Abstract
The methodology of combining subsamples into a single “composite” sample representative of an entire river reach is examined. Current methods of characterizing the overall grain-size distribution of a river reach are inadequate because they either require enormous amounts of material to be collected, are inherently biased, or fail to describe the local variations occurring within the sampled region. These problems can be overcome by employing the grid-by-number sampling technique. Criteria for obtaining an unbiased grid composite sample as well as its overall accuracy are provided. It is proposed that local variations in a river reach's grain-size distribution can be located by comparing the arithmetic means of adjacent subsamples through the use of statistical hypothesis testing. By systematically comparing the arithmetic means of adjacent subsamples throughout the area of interest and using a moving windows approach to locate sudden changes in a sediment's grain-size distribution more precisely, the local variability of the river reach can be described adequately.
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References
1.
Church, M. A., and Kellerhals, R.(1978). “On the statistics of grain size variation along a gravel river.”Can. J. Earth Sci., 15(7), 1151–1160.
2.
Church, M. A, McLean, D. G., and Wolcott, J. F. (1987). “River bed gravels: sampling and analysis.”Sediment transport in gravel bed rivers, C. R. Thorne, J. C. Bathurst, and R. D. Hey, eds., John Wiley and Sons, Ltd., London, U.K., 43–88.
3.
Crowder, D. W., and Diplas, P. (1994). “Some benefits of grid by number sampling.”Hydraulic engineering 94, G. V. Cotroneo, and R. R. Rumer, eds., ASCE, New York, N.Y., 795–799.
4.
Diplas, P., and Sutherland, A. J.(1988). “Sampling techniques of gravel sized sediments.”J. Hydr. Engrg., ASCE, 114(5), 484–501.
5.
Fripp, J. B., and Diplas, P.(1993). “Surface sampling in gravel streams.”J. Hydr. Engrg., ASCE, 119(4), 473–490.
6.
International Standards Organization (1977). “Liquid flow measurements in open channels—bed materials sampling.”ISO 4364-1977(E), Geneva, Switzerland.
7.
Kellerhals, R., and Bray, D. I.(1971). “Sampling procedures for coarse fluvial sediments.”J. Hydr. Engrg. Div., ASCE, 103(8), 1165–1180.
8.
Mosley, M. P., and Tindale, D. S.(1985). “Sediment variability and bed material sampling in gravel-bed rivers.”Earth Surface Processes, 10(5), 465–482.
9.
Naot, D.(1984). “Response of channel flow to roughness heterogeneity.”J. Hydr. Engrg. Div., ASCE, 110(3), 1569–1587.
10.
Ott, L. (1988). An introduction to statistical methods and data analysis, 3rd Ed., PWSKent Publishing Co., Boston, Mass.
11.
Rice, S., and Church, M.(1996). “Sampling surficial fluvial gravels: the precision of size distribution percentile estimates.”J. of Sedimentary Res., 66(3), 654–665.
12.
Seal, R., Parker, G., and Paola, C. (1993). “The effect of local patchiness of gravel grain size distributions on bed load transport in braided rivers.”Advances in hydro-science and engineering, S. Y. Wang, ed., Vol. 1, Ctr. for Computational Hydroscience and Engrg. Univ. of Mississippi, University, MS. 1331–1338.
13.
Sommer, K. (1986). Sampling of powders and bulk materials. Springer-Verlag KG. Berlin, Heidelberg, Germany.
14.
Townshend, C. R.(1989). “The patch dynamics concept of stream ecology.”J. of the North Am. Benthological Soc., 8(1), 36–50.
15.
Weiss, N. A., and Hasset, M. J. (1991). Introductory statistics, 3rd Ed., Addison-Wesley Publishing Co., Reading, Mass.
16.
Wolcott, J., and Church, M.(1991). “Strategies for sampling spatially heterogeneous phenomena: the example of river gravels.”J. of Sedimentary Petrology, 61(4), 534–543.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 123 • Issue 12 • December 1997
Pages: 1106 - 1117
Copyright
Copyright © 1997 American Society of Civil Engineers.
History
Published online: Dec 1, 1997
Published in print: Dec 1997
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