ANALYSIS PROCEDURE FOR AND APPLICATION OF A DEVICE FOR SIMULATING SEDIMENT ENTRAINMENT

The problem of estimating entrainment rates for cohesive bed sediments has been approached. An analysis procedure was developed for characte rizing entrainment of cohesive bed sediments using a device called a P article Entrainment Simulator (PES), which simulates bed shear effects on sediment entrainment. While most of the available techniques to ca lculate entrainment rates are based on theoretical parameterizations u sing the flow field, the PES technique and its method of analysis prov ide a tool to directly measure entrainment, under controlled laborator y settings, representative of existing or predicted conditions of bed stress, sediment compaction and cohesion, and (if any) bioturbation. T he analysis procedure calculates entrainment rates using data generate d from experiments conducted on sediment cores with the PES. The proce dure was applied to determine entrainment rates for two different mari ne sites. The first, in Puget Sound, was used to validate the procedur e with field data for a tidally-dominated period of time. Entrainment rates were calculated at a second site on Hudson Shelf Valley where st orm generated wave and current effects are important. Suspended sedime nt concentration distributions in the water column were calculated at both sites using PES-generated entrainment-stress functions. Good agre ement was reached between the calculated and observed suspended sedime nt concentrations at 5 m above the bed for the Puget Sound application . Observations were not available for suspended sediment concentration comparisons for the Hudson Shelf Valley application.