Cohesive Sediment Entrainment Rate Functions: Expanding and Quantifying their Parameterizations

摘要

The erosion characteristics of cohesive sediments in nearshore environments depend on a number of biogeochemical processes. It is standard practice to experimentally determine the entrainment rate of sediment into the water column as a function of the applied bottom shear stress and fit this data to a power law function. This work addresses the inherent problems of fitting entrainment rate data to parameterized functions, focusing on the non- uniqueness of the power law approach and its sensitivity to errors in the data. An approach for incorporating the effects of bioturbation and consolidation, thus expanding the parameter space of the entrainment function, into the standard power law formulation is examined with regard to its physical sensitivity and its expanded predictive capability of biogeochemical changes in cohesive sediments. Finally, power law and exponential entrainment functions are compared in order to illustrate the physical sensitivity of a particular entrainment parameterization.