Suspended sediment concentration at z_kmx(bot) Suspended sediment concentration at z_kmx(bot) https://oss.deltares.nl/c/message_boards/find_thread?p_l_id=1806765&threadId=475971 2020-10-21T17:07:52Z 2020-10-21T17:07:52Z Suspended sediment concentration at z_kmx(bot) Shawn Harrison https://oss.deltares.nl/c/message_boards/find_message?p_l_id=1806765&messageId=475970 2014-08-26T03:57:58Z 2014-08-26T03:41:34Z Hi, <br />I&#39;m trying to make sense of the formulation that D3D uses to calculate the source and sink terms for suspended sediment to transfer between the bed and flow. My questions relate to the calculation of suspended sediment concentration near the reference level and kmx layer (see Figure 11.4 in Delft3d-FLOW User manual). <br />1) If the hydrodynamics were calculated for 2D depth-averaged flow, is the entire water column the &#34;kmx layer&#34;? <br />2) Why is C_kmxbot (the concentration of sediment at the bottom of the kmx layer) not equal to C_a (the concentration of sediment in the reference level above the bedforms)? Is there something between these two layers? <br /><br /><br />Another question: <br />If the user chooses to use an alternative sed. transp. formulae than the default Van Rijn (1993) formulation, e.g. The Soulsby/Van Rijn Formula, <br />how does D3D determine the source and sink terms for suspended sediment? I.e. how is the suspended sediment transport (S_s) converted to a reference concentration to feed the advection-diffusion equation for suspended sediment transport? Does the S_s become C_a or the C_kmz in a 2D depth-averaged model? And are the source and sink terms still valid as described in Equation 11.35, 11.36, 11.37, 11.40, 11.41? If so, where do the epsilon_s, alpha1 and alpha2 terms come from, because they are calculated within the Van Rijn (1993) formulae? <br /><br />Thanks for any clarification,<br />Shawn Shawn Harrison 2014-08-26T03:41:34Z