REPRESENTING GRAIN-SIZE OF BED MATERIAL

Median grain size is often used as a representing size in the calculat ion of sediment transport. But, it may not meet the physical mean of s ediment transport completely. Comparison is made on the median grain s ize and the grain size weighting by percentage retained. Two grain siz es are calculated on the basis of the numerous grain size distribution s of bed material collected from offshore western Taiwan. It is shown that the grain size weighting by percentage retained is better than th e median grain size to represent the various grain sizes of bed materi al. In addition, the percentage finer of the grain sizes that takes in to consideration of the the weighting of the percentage retained is in troduced to investigate the influences of grain sizes of bed material on water depth. Copyright (C) 1996 Elsevier Science Ltd