Dear Sir,I found some in the document of EFDC+ theory. And unbalance dimensional unit in continuty equation.https://eemodelingsystem.atlassian.net/wiki/spaces/ETG/pages/2345115/2.1.2+Basic+Hydrodynamic+EquationsIf everyone knows the answer, please let me know.Thank you

2017/12/EFDC-questions.png

Can anyone give me the answer for these strange terms and unbalance units in the governing equations?

Thank you for your question. The terms you are asking about allow for changing the coordinate system. The terms after those in red (mx.my.f.H.v) allow for the the Coriolis effect. In terms of units, they are consistent as mx, my, m, and dz are all dimensionless. So Sh is m/s. We have updated the page to make this clearer.

Thank you very much for your response. It is clear now. I have another question. In EFDC, the bed shear stress is calculated using the depth-averaged velocity as following formula, right?τ_0=ρC_D U ̅^2In whichρ water densityC_D drag coefficientU ̅ depth – averaged current velocityOr it used the velocity at the near bottom layer only?Thank you,Wang

It is just near the bottom layer only. At the bed, the stress components are related to the near bed or bottom layer velocity components by the quadratic resistance formulation provided here:https://eemodelingsystem.atlassian.net/wiki/spaces/ETG/pages/2356315/2.2.1+Bottom+Friction