User Guide 025

14 Appendix D: Determining the sediment size Classes

In order to determine the appropriate grain sizes for a simulation it is useful to be able to determine ahead of time the size class fractions using a log-normal distribution for different median grain sizes and sorting. The Matlab example below determines the grain size distribution given the smallest and largest grain sizes, number of sediment sizes, median grain size and geometric standard deviation. The figure shows the computed grain size distribution.

matlab code

Figure E-1. Computed grain size distribution from the Matlab script above.