AN ESTIMATION METHOD OF EQUILIBRIUM GRAIN SIZE DISTRIBUTION IN INNER BAY

Abstract

A grain size distribution of suspended solids or sediment in a closed basin is closely related to habitat suitability of aquatic benthic animals such as coral or a shellfish. However, it is very difficult to get correct information about an equilibrium grain size distribution because it always changes spatially and temporally. We investigated a method to estimate grain size distributions both of bed load material and suspended one by using bottom friction velocities which were calculated by wave analysis based on statistical wave data. And then, we assume that the equilibrium grain size distribution of sediment can be approximated with the mean value of bed load material and suspended load material. We applied this method to estimate the grain size distributions of sediment in the Takegashima Marine Park which is located the southern end of Tokushima and the estimated grain size distributions coincide with the field data.