Sediment concentration

During the cohesive sediment model configuration process, I want to know how to set the sediment concentration near the bed which is
prerequisite for calculate the deposition flux. Thank you.

The sediment concentration near the bed is the equilibrium layer. In EFDC the concentration is not specified, rather the approach to calculate it is selected and it is then computed dynamically during the model run. The options include: Garcia & Parker, Van Rijn, Smith & Mc Lean etc. These options are available in Sediment > Sediment Transport Options > Modify > Non Coh Susp > Equilibrium Concentration.

Thank you very much.

you means that if the cohesive sediment is modelled, then the non-cohesive is must modelled also with it ? Thank you.

We think you mean sediment mass rather than sediment concentration. Sediment concentration only refers to re-suspension of non-cohesives. That is the issue that was addressed above. It is not necessary to model non-cohesives if you only want to model cohesives.

If want to set initial conditions for cohesives then you have four options (Sediments > Sediment Transport Options > Modify > Initial Conditions > Sediment Initial Conditions options), which are: constant WC and bed conditions, spatially varying WC, spatially varying bed conditions, or spatially varying WC and bed. If you have variable sediment mass in the sediment layer then need to set it appropriately in the spatially varying bed conditions.