On the temporal-spatial variation of sediment size distributions
A mathematical-physical model for the effect of erosion and deposition on the temporal and spatial variation of the size distributions of sediments is proposed and investigated. The model is closely related to the logarithmic hyperbolic distribution and preserves the hyperbolic shape of log-size distributions. In order to facilitate specification of the model in applications the concept of a ‘local erosion time’ is introduced. The local erosion time gives the local time scale of grain sorting changes. Explicit formulae for the temporal-spatial variation of the hyperbolic parameters predicted by the model are derived for stable bed forms and alluvial streams. The results are compared to field observations. Also the effect of the spatial gradient of the grain sorting is considered.
KeywordsTransport Rate Sorting Process Hyperbolic Distribution Bedload Transport Rate Linear Dune
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