Hi Sanaz,
please find below some tips:
- Launch a simulation only with suspended sediment transport only to see how your system behaves.
- Try another formula for the equilibrium concentration, ex. = 1
- Unless needed, remove unnecessary keywords, ex. SKIN FRICTION CORRECTION = 2
- Force the use of a numerical scheme, ex. SCHEMA POUR LA CONVECTION DES SEDIMENTS EN SUSPENSION = 13
- Last but not least, be aware that solving suspended sediment transport means the solution of an advection-diffusion equation, you'll probably need to reduce your time step...
Hope it helps,
Best wishes,
Pablo