Son, M.; Bombardelli, F.A.; Park, B., and Byun, J., 2018. On the Inverse Relationship between Concentration and Size of Cohesive Sediment. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 56–70. Coconut Creek (Florida), ISSN 0749-0208.

It is well accepted that the size of floc, the aggregate of cohesive sediment, increases through flocculation processes under high-mass-concentration conditions. However, field studies often show the inverse relationship between floc size and concentration. To examine the mechanism of such inverse relationship, numerical simulations using a robust 1DV model are carried out in this work. At relatively low elevations, the size of floc often has an inverse relationship with concentration under the hydrodynamic conditions of tidal flow and steady current. Nonetheless, the size of floc is proportional to concentration at high elevations. When the inverse relationship exists, the inversion of parameter representing the ratio between aggregation intensity and breakup intensity is found as the hydrodynamics becomes weak. From the findings, it is deduced that the floc size is affected by non-linear interactions between turbulence and concentration. None of them can be used to parameterize the tendency of size variation solely.