Using the hyperbolic distribution to estimate the precision of size distribution percentiles of fluvial gravels

The hyperbolic distribution is fitted to published grain-size data collected from the surface of two gravel-bed rivers (the Fraser and Mamquam River data sets of Rice and Church). Our parametric approach enables calculation of standard errors for estimates of percentiles, as an alternative to the use of the bootstrap for this purpose. For estimation, we have used the statistical package R and the advantages of this software for this type of analysis are highlighted in this paper.